Connecting to the Internet Using Cellular Data Networks
When you don’t have a Wi-Fi network available or you don’t want to use one that is available (such as if it has a fee or is slow), your iPhone can connect to the Internet through a cellular data network.
The provider for your iPhone also provides a cellular data connection your iPhone uses to connect to the Internet automatically when you aren’t using a Wi-Fi network (such as when you are in a location that doesn’t have one). (Your iPhone tries to connect to an available Wi-Fi network before connecting to a cellular data connection, because Wi-Fi is typically less expensive and faster to use.) These cellular networks cover large geographic areas and the connection to them is automatic; your iPhone chooses and connects to the best cellular network currently available. Access to these networks is part of your monthly account fee; you choose from among various amounts of data (ideally, you can choose an account with unlimited data) per month for different monthly fees.
Most providers have multiple cellular data networks, such as a low-speed network that is available widely and one or more higher-speed networks that have a more limited coverage area.
The cellular data networks you can use are determined based on your provider, your data plan, the model of iPhone you are using, and your location within your provider’s networks or the roaming networks available, when you are outside of your provider’s coverage area. The iPhone automatically uses the fastest connection available to it at any given time (assuming you haven’t disabled that option, as explained later).
In the United States, the major iPhone providers are AT&T, Verizon, T-Mobile, and Sprint. There are also other smaller providers, such as Virgin Mobile. All these companies offer high-speed Long Term Evolution (LTE) cellular networks (these are also referred to as true 4G networks) along with the slower 4G and 3G networks. In other locations, the names and speeds of the networks available might be different.
The following information is focused on LTE networks because I happen to live in the United States and use AT&T as my cell phone provider. If you use another provider, you are able to access your provider’s networks similarly, though your details might be different. For example, the icon on the Home screen reflects the name of your provider’s network, which might or might not be LTE.
LTE high-speed wireless networks provide very fast Internet access from many locations. (Note: LTE networks might not be available everywhere, but you can usually access them near populated areas.) To connect to the LTE network, you don’t need to do anything. If you aren’t connected to a Wi-Fi network, you haven’t turned off LTE, and your iPhone isn’t in Airplane mode, the iPhone automatically connects to an LTE network when available. When you are connected to the LTE network, you see the LTE indicator at the top of the iPhone’s screen. If you can’t access the LTE network, such as when you aren’t in its coverage area, the iPhone automatically connects to the next fastest network available, such as 4G. If that isn’t available, it connects to the next fastest and so on until it finds a network to which it can connect if there is one available. If it can’t connect to any network, you see No Service instead of a network’s name; this indicates that you currently can’t connect to any network, and so you aren’t able to access the Internet.
One thing you do need to keep in mind when using a cellular network is that your account might include a limited amount of data per month. When your data use exceeds this limit, you might be charged overage fees, which can be very expensive. Most providers send you warning texts or emails as your data use approaches your plan’s limit, at which point you need to be careful about what you do while using the cellular data network to avoid an overage fee. Some tasks, such as watching YouTube videos or downloading large movie files, can chew up a lot of data very quickly and should be saved for when you are on a Wi-Fi network to avoid exceeding your plan’s monthly data allowance. Other tasks, such as using email, typically don’t use very much data.
When you move outside your primary network’s geographic coverage area, you are in roaming territory, which means a different provider might provide cellular phone or data access, or both. The iPhone automatically selects a roaming provider, if there is only one available, or allows you to choose one, if there is more than one available.
When you are outside of your primary provider’s coverage area, roaming charges can be associated with calls or data use. These charges are often very expensive. The roaming charges associated with phone calls are easier to manage, because it’s more obvious when you make or receive a phone call in a roaming area. However, data roaming charges are much more insidious, especially if Push functionality (where emails and other updates are pushed to your iPhone from the server automatically) is active. And when you use some applications, such as Maps to navigate, you don’t really know how much data is involved. Because data roaming charges are harder to notice, the iPhone is configured by default to prevent data roaming. When data roaming is disabled, the iPhone is unable to access the Internet when you are outside of your cellular network, unless you connect to a Wi-Fi network. (You can still use the cellular roaming network for telephone calls.)
You can configure some aspects of how your cellular network is used, as the following task demonstrates. You can also allow individual apps to use, or prevent them from using, your cellular data network. This is especially important when your data plan has a monthly limit (if you have an unlimited plan, you don’t need to bother).
In most cases, the first time you launch an app, you’re prompted to allow or prevent it from using cellular data. At any time, you can use the Cellular Data options in the Settings app to enable or disable an app’s access to your cellular data network.
The options you have for configuring how your iPhone uses its cellular data connection depend on the provider your iPhone is connected to and the model of iPhone you use. For example, if you live in the United States and use Sprint as your cellular provider, the Cellular screens in the Settings app look a bit different than the figures in this section (which are based on AT&T’s service). Regardless of the specific options you see on your phone, the basic purpose is the same, which is to configure how your iPhone uses its high-speed network and to enable and disable roaming.
Configuring Cellular Data Use
The following steps show configuring cellular data use on an iPhone using AT&T in the United States; you can use similar steps to configure these options on an iPhone from a different provider:
Open the Settings app.
To use a cellular Internet connection, set the Cellular Data switch to on (green) and move to step 4; if you don’t want to use a cellular Internet connection, set this switch to off (white) and skip the rest of these steps. To use the Internet when the Cellular Data switch is off, you have to connect to a Wi-Fi network that provides Internet access.
Tap Cellular Data Options.
To configure the high-speed network, tap Enable high-speed network, where high-speed network is the name of the high-speed network your provider has. With some providers, this is a switch that enables or disables the high-speed network; set the switch to be on or off and skip to step 8 (if you set the switch to off, the iPhone can’t use the higher-speed network, but can use slower networks).
To disable the high-speed network, tap Off; to use it for both voice and data, tap Voice & Data; or to use it only for data, tap Data Only. (When you enable the high-speed network for voice, the quality of the sound of your calls might be better.)
Tap the Back icon (<).
If you want to allow data roaming, slide the Data Roaming switch to the on (green) position. With some providers, Roaming is an option instead of a switch; tap Roaming and use the resulting switches to enable or disable roaming for voice or data and then tap the Back icon (<). You should usually leave Data Roaming off so that you don’t unknowingly start using roaming (which can lead to high fees) should you be moving around a lot. You can then enable it as needed so you know exactly when roaming is on.
Tap the Back icon (<).
Use the controls in the PROVIDER section, where PROVIDER is the name of your provider, to configure how the cellular service interacts with other services, such as to enable Wi-Fi calling, calls on other devices, and so on. These settings are explained in Chapter 7, “Communicating with the Phone and FaceTime Apps.”
Swipe up the screen until you see the CELLULAR DATA section. This section enables you to allow or prevent individual apps from accessing a cellular data network. To limit the amount of data you use, it’s a good idea to review this list and allow only those apps that you rely on to use the cellular data network. (Of course, if you are fortunate enough to have an unlimited cellular data plan, you can leave cellular data for all the apps enabled.) This list can be quite long if you have a lot of apps stored on your iPhone.
Set an app’s switch to on (green) if you want it to be able to use a cellular data network to access the Internet.
Set an app’s switch to off (white) if you want it to be able to access the Internet only when you are connected to a Wi-Fi network.
Set the Wi-Fi Assist switch to on (green) if you want your iPhone to automatically switch to its cellular connection when the Wi-Fi connection is weak. If you have a limited cellular data plan, you might want to set this switch to off (white) to minimize cellular data use. If you have an unlimited plan, you should leave this on.
If you want to access files on your iCloud drive when you aren’t using a Wi-Fi network, set the iCloud Drive switch to on (green). If you set this switch to off, files are synced the next time you connect to a Wi-Fi network. Like the other areas, if you have an unlimited data plan, you can leave this enabled, but if you do have a limit, you might want to disable it.