Controlling Network Data
Your iPhone gives you fairly precise control over your network data. For example, you can toggle just the LTE data, all cellular data, data roaming, or all your iPhone antennas. The next few sections provide the details.
Turning off LTE
Using the LTE cellular network is a real pleasure because it's so much faster than a 3G connection (which, in turn, is much faster than a molasses-in-January EDGE connection). If LTE has a downside, it's that it uses up a lot of battery power. That's true even if you're currently connected to a Wi-Fi network, because the LTE antenna is constantly looking for an LTE signal. If you'll be on your Wi-Fi network for a while, or if your battery is running low and you don't need an LTE cellular connection, you should turn off the LTE antenna to reduce the load on your iPhone's battery. Here's how:
- On the Home screen, tap Settings. The Settings app appears.
- Tap General to open the General screen.
- Tap Cellular. The Cellular screen opens.
- Tap the Enable LTE switch to Off.
Turning off cellular data
If you've reached the limit of your cellular data plan, you almost certainly want to avoid going over the cap because the charges are usually prohibitively expensive. As long as you have a Wi-Fi network in range, or you're disciplined enough not to surf the web or cruise YouTube when there's no Wi-Fi in sight, you'll be okay. Still, accidents can happen. For example, you might accidentally tap a link in an e-mail message or text message, or someone in your household might use your phone without knowing about your restrictions.
To prevent these sorts of accidents (or if you simply don't trust yourself when it comes to YouTube), you can turn off cellular data altogether, which means your iPhone only accesses Internet data if it has a Wi-Fi signal. Follow these steps to turn off cellular data on your iPhone:
- On the Home screen, tap Settings. The Settings app appears.
- Tap General to open the General screen.
- Tap Cellular. The Cellular screen opens.
- Tap the Cellular Data switch to Off.
Now, if you try to access the Internet without a Wi-Fi connection, you see the dialog shown in Figure below. If you really must connect, you can tap Settings to jump directly to the Network screen.
Controlling cellular data usage
Rather than turning off cellular data completely, you can take a more targeted approach. For example, if you're a bit worried about going over your cellular plan's data ceiling, it makes sense to avoid relatively high-bandwidth items, such as FaceTime and iTunes, but not relatively low-bandwidth content, such as iCloud documents and Safari's reading list.
You could just police this yourself but, hey, you're a busy person and you might forget the next time a FaceTime call comes in and you're in a cellular-only neighborhood. I say leave the details to your iPhone by configuring it to not allow certain content types over a cellular connection. Here's how:
- On the Home screen, tap Settings. The Settings app appears.
- Tap General to open the General screen.
- Tap Cellular. The Cellular screen opens.
- In the Use Cellular Data for section, tap the switch to Off for each type of content you want to ban from cellular.
Turning off data roaming
Data roaming is an often-convenient cell phone feature that enables you to make calls - and, with your iPhone, surf the web, check and send e-mail, and exchange text messages - when you're outside of your normal coverage area. The downside is that roaming charges are almost always eye-poppingly expensive. You're often talking several dollars per minute, depending on where you are and what type of service you're using.
Unfortunately, if you have your iPhone's Data Roaming feature turned on, you may incur massive roaming charges even if you never use your phone! That's because your iPhone still performs background checks for things like incoming e-mail messages and text messages, so a week in some far-off land could cost you hundreds of dollars without even using your phone.
To avoid this insanity, turn off your iPhone's Data Roaming feature when you don't need it. Follow these steps:
- On the Home screen, tap Settings. The Settings app appears.
- Tap General. The General screen appears.
- Tap Cellular. The Cellular screen appears.
- Tap the Data Roaming switch to Off.
Switching your iPhone to airplane mode
When you board a flight, aviation regulations in most countries are super strict about cell phones - no calls in and no calls out. In fact, most of those regulations ban wireless signals of any kind. This means your iPhone is a real hazard to sensitive airline equipment because it transmits Wi-Fi and Bluetooth signals, even if there are no Wi-Fi receivers or Bluetooth devices within 30,000 feet of your current position.
Your pilot or friendly flight attendant will suggest that passengers simply turn off their phones. Sure, that does the job, but darn it, you've got an iPhone, which means there are plenty of things you can do outside of its wireless capabilities, such as listen to music or an audiobook, watch a show, view photos, and much more.
So how do you reconcile the no-wireless-and-that-means-you regulations with the iPhone's multitude of no-wireless-required apps? You put your iPhone into a special state called airplane mode. This mode turns off the transceivers - the internal components that transmit and receive wireless signals - for the phone, Wi-Fi, and Bluetooth features. With your iPhone now safely in compliance of federal aviation regulations, you're free to use any app that doesn't rely on wireless transmissions.
Follow these steps to activate airplane mode:
- On the Home screen, tap Settings. The Settings app appears.
- Tap the Airplane Mode switch to turn this setting On. Your iPhone disconnects your cellular network and your wireless network (if you have a current connection). Notice, as well, that while airplane mode is on, an Airplane icon appears in the status bar in place of the Signal Strength and Network icons.
Note:
If a flight attendant sees you playing around with your iPhone, he or she may ask you to confirm that the phone is off. (One obviously iPhone-savvy attendant even asked me if my phone was in airplane mode.) Showing the Airplane icon should be sufficient.