CompTIA A+ Exam Cram: Mobile Device Hardware and Operating Systems

This chapter is from the book 

Mobile Networking and Synchronization

Now that we’ve discussed mobile hardware and software, let’s go ahead and harness their power through networking and synchronization.

From cellular GSM connections to Wi-Fi and Bluetooth, a mobile device can create connections to computers and networks, download e-mail, and work with headsets and remote printers.

Synchronization is the matching up of files, e-mail, and other types of data between one computer and another. We use synchronization to bring files in line with each other and to force devices to coordinate their data. When dealing with synchronization, a mobile device can connect to a PC via USB (the most common), RS-232 serial connections (less common), Wi-Fi, and Bluetooth.

GSM Cellular Connectivity

Cellular phones use the Global System for Mobile Communications (GSM) to make voice calls, and GSM or the general packet radio service (GPRS) to send data at 2G speeds through the cellular network. Extensions of these standards, 3GPP and EDGE are used to attain 3G speeds. 4G speeds can be attained only if a mobile device complies with the International Mobile Telecommunications Advanced (IMT-Advanced) requirements, has a 4G antenna, and is in range of a 4G transmitter, which as of the writing of this book, are only common in urban areas.

Most devices cannot shut off the cellular antenna by itself (unless shutting down the whole device.) However, every device manufactured now is required to have an “airplane mode,” which turns off any wireless antenna in the device including GSM, Wi-Fi, GPS, and Bluetooth. On a typical Android device, this can be done by going to Settings > Wireless & Networks > and check marking Airplane Mode. You will find that some airlines don’t consider this to be acceptable and will still ask you to turn off your device, either for the duration of the flight or at least during takeoff and landing. Android devices can also access Airplane Mode by pressing and holding the power button. To enable airplane mode on an Apple tablet you would go to Settings > Airplane Mode.

Wi-Fi Network Connectivity

Using a cellular connection can be slow when transmitting data (unless you happen to get a 4G signal). That’s why all mobile devices are equipped with an embedded wireless antenna to connect to wireless LANs. This WLAN antenna (often referred to as a Wi-Fi antenna) can allow access to 802.11a, b, g, and n networks. The wireless configuration works similar to a wireless connection on a PC or laptop. See Chapter 15, “Networking,” for a detailed description of connecting to wireless networks.

In general, the mobile device must first search for wireless networks before connecting. On a typical Android smartphone, this can be done in the following steps:

1. Go to Settings > Wireless & Networks > Wi-Fi Settings.
2. From there, most devices usually scan for wireless networks automatically, or you could tap Add Wi-Fi Network to add one manually.
3. If adding a network manually, enter the SSID of the wireless access point in the Add Wi-Fi Network window, as shown in Figure 17.4.
   

   Figure 17.4. Android OS Prompting for the user to enter an SSID

4. Enter the passcode for the network. If the code is correct, then the wireless adapter in the mobile device gets an IP address allowing it to communicate with the network. If a wireless network uses WPA2, and the mobile device isn’t compatible, you should search for an update to the operating system to make it WPA2-compliant.

Follow these steps to access wireless networks on an iPad or similar device:

1. Go to Settings > Wi-Fi.
2. The device usually scans for networks automatically. To connect to a network manually, tap Other.
3. If adding a network manually, type the SSID of the network in the Name field.
4. Type the passcode for the network. If adding the network manually, you can select the type of security, for example WPA2, as shown in Figure 17.5.

Almost all types of devices display the universal wireless icon when connected to a wireless network, as shown in Figure 17.6. This icon not only let’s you know when you are connected, but also how strong the connection is. The more curved lines you see, the better the connection.

Some mobile devices can also perform Wi-Fi tethering. This is when the mobile device shares its Internet connection with other Wi-Fi capable devices. For example, if one user had a smartphone that could access the Internet through 3G or GPRS networks, then it could be configured to become a portable Wi-Fi hotspot for other mobile devices that are Wi-Fi capable but have no cellular or GPRS option. Another option in Android is USB tethering. When an Android phone is connected to a desktop computer via USB, the desktop (Windows or MAC) can share the phone’s mobile network.

A lot of devices can also be configured for Internet pass-through as well. This means that the phone or other device connects to a PC via USB and accesses the Internet using the PC’s Internet connection.

Wi-Fi Troubleshooting

When troubleshooting mobile device wireless connections, always make sure of the following basic wireless troubleshooting techniques:

• Device is within range.
• The correct SSID was entered (if manually connecting).
• The device supports the encryption protocol of the wireless network.
• Wi-Fi tethering or Internet pass-through is not conflicting with the wireless connection.

If you still have trouble, here are a few more methods that can help to connect, or reconnect to a wireless network:

• Power cycle the mobile device.
• Power cycle Wi-Fi.
• Remove or “forget” the particular wireless network and then attempt to connect to it again.
• Access the advanced settings and check if there is a proxy configuration, if a static IP is used, or if there is a Wi-Fi sleep policy. Any of these could possibly cause a conflict. You might also try renewing the lease of an IP address, if the device is obtaining one from a DHCP server (which it most likely will be.) Some devices also have an option for Best Wi-Fi Performance, which uses more power but might help when connecting to distant WAPs. Advanced settings can be found on an Android device by going to Settings > Wireless and Networks > Wi-Fi Settings; then tap the Menu button and select Advanced. This is shown in Figure 17.7. On an Apple iPad advanced settings can be located at Settings > Wi-Fi; then tap on the arrow of an individual wireless network. This is shown in Figure 17.8.

One of these methods usually works when troubleshooting a wireless connection but if all else fails; a hard reset can bring the device back to factory settings. (Always back up all data and settings before performing a hard reset.) And if the mobile device still can’t connect to any of several known good wireless networks, bring the device to an authorized service center.

Bluetooth Configuration

Bluetooth is a wireless standard for transmitting data over short distances. It is commonly implemented in the form of a headset or printer connection by mobile users. It is also used to create wireless personal area networks (WPANs) consisting of multiple Bluetooth-enabled mobile devices.

By default, Bluetooth is usually disabled on Android devices but is enabled on devices such as iPads. To connect a Bluetooth device to a mobile device, Bluetooth first needs to be enabled. Then the Bluetooth device needs to be synchronized to the mobile device. This is known as pairing or linking. It sometimes requires a pin code. When synchronized, the device needs to be connected. Finally, the Bluetooth connection should be tested. Following are the steps involved in connecting a Bluetooth headset to a typical Android-based device and to an iPad. Before you begin, make sure the Bluetooth headset is charged.

Steps to Configure a Bluetooth Headset on an Android-based Device

1. Go to Settings > Wireless & Networks > and check the box for Bluetooth. This enables Bluetooth on the mobile device.
2. Tap Bluetooth Settings. This displays the Bluetooth Setting screen.
3. Prepare the headset. This can vary from headset to headset. For example, on a typical Motorola Bluetooth headset, you press and hold the button while opening the microphone. Keep holding the button.
4. Tap Scan for Devices on the Android device. Keep holding the button on the headset until the Android device finds it.
5. On the Android device, under the Bluetooth device tap Pair with This Device. Most Android devices pair the Bluetooth headset to the mobile device and then complete the connection automatically, allowing full use of the device.
6. Enter a pin code if necessary. Many devices come with a default pin of 0000.

When finished, the screen on the Android device will look similar to Figure 17.9. Note the Bluetooth icon at the top of the screen. This icon tells you if Bluetooth is running on the device. It will remain even if you disconnect the Bluetooth device. For this headset device we would test it simply by making a phone call. To disconnect it, simply tap the device on the screen and tap OK. It will remain paired but nonfunctional until a connection is made again.

Mobile devices can also connect to other Bluetooth-enabled devices (forming a PAN), or to a computer equipped with a Bluetooth dongle. To do this, you must set the mobile device to discoverable (which generally lasts for only 2 minutes). In the same fashion that the headset was discovered by the mobile device in the previous procedure, so can a mobile device be discovered by a computer or other mobile device. When connecting a mobile device to another mobile device or PC, it can be identified by its name. For example, the mobile device in Figure 17.9 is listed as PG06100. You can modify this name if you want. It is authenticated by a pin code chosen at the PC or other mobile device. We would test these types of connections by sending data or by initiating communications.

Steps to Configure a Bluetooth Headset on an iOS-based Device

This exercise refers to an iPad2.

1. Go to Settings > General > and tap Bluetooth. This displays the Bluetooth screen.
2. Tap Bluetooth to enable it (if it isn’t enabled already). This automatically starts searching for devices and continues to do so.
3. Prepare the headset. This can vary from headset to headset. For example, on a typical Motorola Bluetooth headset, you press and hold the button while opening the mic. Keep holding the button. The iPad2 will automatically recognize the device and list it as discoverable.
4. Tap the device name, and it should automatically connect, as shown in Figure 17.10.
   

   Figure 17.10. Installed Bluetooth device on an iPad2

5. Enter a pin code if necessary.

To remove the device, click it, and on the next screen click Forget.

Bluetooth devices can be connected to only one mobile device at a time. If you need to switch the Bluetooth device from one mobile device to another, be sure to disconnect it or “forget” it from the current connection before making a new one.

Bluetooth Troubleshooting

If you have trouble pairing a Bluetooth device, and connecting or reconnecting to Bluetooth devices or PANs, try some of the following methods:

• Make sure the phone or other mobile device is Bluetooth-capable.
• Verify that your devices are fully charged, especially Bluetooth headsets.
• Check if you are within range. For example Class 2 Bluetooth devices have a range of 10 meters.
• Try restarting the mobile device and attempt to reconnect.
• Check for conflicting Wi-Fi frequencies. Consider changing the channel used by the Wi-Fi network.
• Try using a known good Bluetooth device with the mobile device to make sure that the mobile device’s Bluetooth is functional.
• Remove or “forget” the particular Bluetooth device; then turn off Bluetooth in general, restart the mobile device, and attempt to reconnect.

E-Mail Configurations

Though there are many other types of communication available to mobile users, e-mail still accounts for an important percentage. You should know how to configure a mobile device for web-based e-mail services such as Gmail, Yahoo, and so on. You should also know how to configure POP3, IMAP, and connections to Microsoft Exchange Servers.

Web-Based E-Mail for Mobile Devices

Mobile devices can access web-based e-mail through a browser, but this is not necessary nowadays due to the “app.” For example, Android devices come with a Gmail application built in, allowing a user to access Gmail directly without having to use the browser. Apple iOS devices allow connectivity to Gmail, Yahoo, and a host of other e-mail providers as well.

Connecting to these services is simple and works in a similar fashion as when working on a desktop or laptop computer. Choose the type of provider you use, enter a username (the e-mail address) and password (on Apple devices an Apple ID is also required), and the user will have access to web-based e-mail.

When troubleshooting issues with e-mail, make sure that the username and password are typed correctly. Using onscreen keyboards often leads to mistyped passwords. Also make sure that the mobile device is currently connected to the Internet.

POP3, IMAP, and Exchange

If you need to connect your mobile device to a specific organization’s e-mail system, it gets a little bit more complicated. You need to know the server that you want to connect to, the port you need to use, and whether security is employed.

Here’s a step-by step process on how to connect a typical Android smartphone to a POP3 account.

1. Go to Home and tap the menu button. Then select All apps.
2. Scroll down until you see the Mail app, and tap it. (This might also be listed as E-mail.)
3. Select whether you want POP3, IMAP, or Exchange. (For this exercise select POP3.)
4. Type the e-mail address and the password of the account and tap Next.
5. Configure the incoming settings. Change the username if desired to something different than the e-mail address. Then type the POP3 server name. By default it will be the domain name portion of the e-mail address, which is usually correct. If security is used select SSL or TLS. This information should be supplied by the network administrator. Type the port number. For POP3 this is 110 by default. If port numbers are different, they will also be supplied to you by the network administrator. Then tap Next.
6. Configure the outgoing settings. Type the SMTP server. Organizations will often use the same server name as the POP3 server. However, small office and home users might have to use their ISP’s SMTP server. If security is used, select SSL or TLS. Type the port number for SMTP, which is 25. (Again, this is a default.) Then tap Next.
7. Configure account options. From here you can tell the mobile device how often to check for mail and whether to notify you when it arrives. Tap Next. At this point, new e-mail should start downloading.
8. Finally, you can give the account an easier name for you to remember it by. Tap Done.

Adding an e-mail account to an iOS-based device works essentially the same, but the navigation will be slightly different. For example, to add an e-mail account to an iPad2, go to Home > Settings > Mail, Contact, Calendars > Add Account > Other > Add Mail Account. Then type the information in the same manner you would in the previous steps.

Now, if you instead have to connect an IMAP account, you have to type the IMAP server (for downloading mail) which uses port 143 by default, and the outgoing SMTP server (for sending mail). If you connect to a Microsoft Exchange mail server, that server name often takes care of both downloading and uploading of e-mail. You might need to know the domain that the Exchange server is a member of. Secure e-mail sessions require the use of SSL or TLS on port 443. Check with the network administrator to find out which protocol to use. POP3 also has a secure derivative known as APOP, a challenge/response protocol which uses a hashing function to prevent replay attacks during an e-mail session. This protocol can be chosen from the Android platform, and is also used by Mozilla Thunderbird, Windows Live Mail and Apple Mail.

Configuring e-mail accounts for other devices, such as the Blackberry, works in a similar fashion to other smartphones. However, you also have the option to connect to a Blackberry Enterprise Server, which is similar to Microsoft Exchange. These Blackberry servers are at the core of “pushed” e-mail, which Blackberry pioneered for users to get their e-mail immediately when it reaches the mail server.

Troubleshooting E-mail Connections

If you have trouble connecting an e-mail account, try some of the following methods:

• Make sure the mobile device has Internet access. If connecting through the cellular network, make sure there is a decent reception.
• Verify that the username, password, and server names are typed correctly. Remember that the username is often the e-mail address itself.
• Check the port numbers. By default POP3 is 110, SMTP is 25, and IMAP is 143. However, network administrators might decide to use nondefault port numbers!

  NOTE

  There is a newer SMTP mail submission port, 587, that can be used by e-mail clients. Due to security concerns with port 25, you will likely see more of port 587 in the future.

• Double-check whether security is required in the form of SSL or TLS. For nonstandard port numbers and security configurations, check with your network administrator.

Synchronizing an Android Device to a PC

If you connect an Android-based mobile device to a PC via USB, Windows will most likely recognize it, and you will have a few options display on the Android screen, as shown in Figure 17.11.

The first option is Charge Only. Aside from charging the Android device by connecting it to an AC outlet, a PC’s USB port can charge it. (Though it will probably take longer to charge.) This first option is the default, so if you need to charge a device only, you won’t have to change this setting. We’ll skip the second option for now and come back to it later. The third option is Disk Drive. If you want to display the contents of the mobile device’s memory card within Windows you have to select this. Then, the device shows up as a Removable Disk in Windows Explorer. From there, data can be copied back and forth between the PC and the mobile device as you usually would within Windows. Older Android devices required you to tap “mount” to have the phone show as a Removable Disk.

You will also note USB tethering on the list. This allows you to share the mobile device’s cellular network with the PC. The last item on the list is Internet Pass-through, which as mentioned previously allows you to use the PC’s Internet connection on the mobile device.

Now, none of these so far allow you to synchronize information from the mobile device to the PC. Only the second option HTC Sync allows this synchronization, but with a caveat: The PC must have the appropriate synchronization software installed. Keep in mind that this software (and connection name) will be different depending on the manufacturer of the device. This example shows an HTC Evo smartphone.

Most synchronization software requires the PC have Windows XP or higher, 1 GB of RAM or more, USB 2.0 ports minimum, and 300 MB of free space on the hard drive. Syncing software is freely downloadable from the manufacturer’s website.

HTC Sync for example can synchronize music, pictures, the calendar, bookmarks and more. This synchronization can be initiated from the mobile device or from the program on the PC. Documents, music, pictures and video will be synchronized by default to the Windows Libraries of the same names.

If you use the mobile device’s built-in contacts and e-mail programs, the information within those programs will be transferred to the PC’s corresponding programs. For example the Calendar and Contacts will be synchronized with Microsoft Outlook. However, for this mobile device, Gmail or Exchange contacts information will not be synchronized, nor will any other third-party data besides data that originates from, or is destined for, a Microsoft application.

However, not everyone uses synchronization software. Some people exclusively use Gmail on the Android platform. Google automatically synchronizes mail, contacts, and the Calendar so that you can view the information on the mobile device or on the PC (when connected to the Gmail website). However, because the data is stored on a Google server, security can be compromised. If you choose to do this, you should use an extremely strong password, change it every month or so, and use a secure browser when connecting to Gmail from your PC. The same people who use Gmail usually transfer data by simply mounting the mobile device as a disk drive in Windows. This effectively renders the synchronization software unnecessary for those people.

Third-party tools (such as Mark/Space) are available if a person wants to synchronize an Android device with a PC or MAC via Bluetooth or Wi-Fi. Standard Microsoft ActiveSync is not used to synchronize data between Android and Windows. However, Exchange ActiveSync can be used to synchronize e-mail, contacts, and calendars between an Android 2.0 mobile device and higher with an Exchange Server.

Synchronizing an iPad2 to a PC

Before getting into synchronizing, let’s talk about charging. The best way to charge an iPad is by plugging the AC adapter into an outlet. If the iPad is connected to a desktop computer via USB and is turned on, it will not charge. However, if it is connected by USB and it is sleeping or off, it will slowly charge. If the computer is not equipped with a high-power USB port, this could take a long time. Regardless, Apple recommends plugging these devices into the AC outlet to charge.

If you plug an iPad into a PC via USB, Windows should automatically recognize it and install the driver for it. At that point you can move files between the PC and the iPad’s memory card. The iPad shows up in Windows Explorer as Apple iPad directly inside of Computer.

To synchronize data such as contacts, calendars, and so on, PC users need to use iTunes for Windows. From iTunes a user would select Sync Contacts or Sync Calendars, for example. This information can be synchronized to Microsoft Outlook 2003 or higher, Windows Address Book (in Windows XP), and Windows Contacts (in Windows 7/Vista). Mac users benefit from the simplicity of synchronization across all Apple products. They can use iTunes or can use the iCloud to store, backup, and synchronize information across all Apple devices. This can be done by USB or via Wi-Fi if the various Apple devices are on the same wireless network. Calendar items can also be synced from the iPad itself by going to Settings > Mail, Contacts, Calendars. Then scroll down and select Sync, as shown in Figure 17.12.

Synchronizing Other Devices

The two operating systems the CompTIA objectives are concerned with are Android and iOS. However, these are not the only players on the field! Let’s mention a few other devices.

First of all, the Blackberry deserves some mention. For the longest time, this was the standard device a business person would use. It has lost some momentum, but you still see plenty of them in the field. Blackberry offers Desktop Software. Separate versions for PC and Mac are available at this link:

http://us.blackberry.com/apps-software/desktop/

The software works in a similar fashion to other synchronization software for Android or iOS.

And let’s not forget about Microsoft mobile operating systems. Windows CE and Windows Mobile are commonly found in the transportation, medical, and surveying fields, as well as other niche markets that require rugged, waterproof devices. These devices synchronize to the PC by way of Microsoft ActiveSync (for Windows XP or earlier) and the Windows Mobile Device Center (Windows Vista or newer.) The Windows Mobile Device Center is available at this link:

http://www.microsoft.com/download/en/details.aspx?id=14

These programs can synchronize data between the mobile device and the PC via USB or Bluetooth connections. Microsoft does not allow synchronization over Wi-Fi as it is deemed a security issue.

Cram Quiz

Answer these questions. The answers follow the last question. If you cannot answer these questions correctly, consider reading this section again until you can.

220-802 Questions

1. Which of the following are valid Wi-Fi troubleshooting methods? (Select the two best answers.)

   	A.	Power cycle the device.
   	B.	Restart Bluetooth.
   	C.	Use a static IP.
   	D.	Make sure the device is within range.
   	E.	Rename the SSID.

2. Which of the following connections requires a username, password, and SMTP server? (Select the two best answers.)

   	A.	Bluetooth connection
   	B.	Wi-Fi connection
   	C.	POP3 connection
   	D.	Exchange connection
   	E.	IMAP connection

3. What is the most common connection method when synchronizing data from a mobile device to a PC?

   	A.	Wi-Fi
   	B.	Bluetooth
   	C.	USB
   	D.	FireWire

4. When configuring a Wi-Fi connection what step occurs after successfully entering the SSID?

   	A.	Select POP3.
   	B.	Check if the device is within range of the WAP.
   	C.	Enter a passcode for the network.
   	D.	Scan for networks.

5. Which technology would you use if you want to connect a headset to your mobile phone?

   	A.	Bluetooth
   	B.	GSM
   	C.	Wi-Fi
   	D.	Exchange

6. Which of the following allows other mobile devices to share your mobile device’s Internet connection?

   	A.	Internet pass-through
   	B.	Locator application
   	C.	IMAP
   	D.	Wi-Fi tethering

7. What would a user need to synchronize contacts from an iPad to a PC?

   	A.	Android Synchronization Application
   	B.	Google Play
   	C.	iTunes
   	D.	ActiveSync

Cram Quiz Answers

220-802 Answers

1. A and D. Valid Wi-Fi troubleshooting methods include power cycling the device and making sure that the mobile device is within range of the wireless access point. Bluetooth could possibly cause a conflict with Wi-Fi. If you suspect this, Bluetooth should simply be turned off. Static IP addresses are one thing you can check for when troubleshooting. Normally, the mobile device should obtain an IP address from a DHCP server. Renaming the SSID of the access point could cause problems for all clients trying to connect. However, you should make sure that the correct SSID was typed (if the connection were made manually.)
2. C and E. POP3 and IMAP e-mail connections require an incoming mail server (either POP3 or IMAP), and an outgoing mail server (SMTP.) Bluetooth and Wi-Fi connections do not require a username or SMTP server. Exchange connections require a username and password, but no SMTP server. The Exchange server acts as the incoming and outgoing mail server.
3. C. USB is the most common connection method used when synchronizing data from a mobile device to a PC. Though Wi-Fi and Bluetooth are also possible, they are less common. Few mobile devices have FireWire connections.
4. C. After you enter the SSID (if it’s correct) you would enter the passcode for the network. POP3 has to do with configuring an e-mail account. If you have already entered the SSID, then you should be within range of the wireless access point (WAP). Scanning for networks is the first thing you do when setting up a Wi-Fi connection.
5. A. The Bluetooth standard is used to connect a headset and other similar devices over short range to a mobile device. GSM is used to make voice calls over cellular networks. Wi-Fi is used to connect mobile devices to the Internet. Exchange is a Microsoft E-mail server; some mobile devices have the capability to connect to e-mail accounts stored on an Exchange server.
6. D. Wi-Fi tethering allows a mobile device to share its Internet connection with other Wi-Fi capable devices. Internet pass-through is when the mobile device connects to a PC to share the PC’s Internet connection. Locator applications are used to find lost or stolen mobile devices through GPS. IMAP is another e-mail protocol similar to POP3.
7. C. PC users need iTunes to synchronize contacts and other data from an iPad to a PC. There are many Android sync programs, but they do not work on Apple devices. Google Play is a place to get applications and other items. ActiveSync is the older Microsoft sync program used to synchronize Windows CE and Mobile to PCs.