View cellular network signal & turn mobile data on or off.
INSTRUCTIONS & INFO
The network signal strength is displayed in the status bar. The more bars, the better the connection. Note:View the AT&T wireless network coverage map.
If iPhone is connected to the Internet via the cellular data network, the 4G, 3G, E, or GPRS icon appears in the status bar. Note: 4G, and 3G service on GSM cellular networks support simultaneous voice and data communications. For all other cellular connections, you can’t use Internet services while you’re talking on the phone unless iPhone also has a Wi-Fi connection to the Internet. Depending on your network connection, you may not be able to receive calls while iPhone transfers data over the cellular network when downloading a webpage, for example. To learn more about the AT&T network, visit http://www.att.com/network
To change cellular network settings, from the home screen, tap Settings.
To turn data roaming on or off, tap the Data Roaming switch. Note:Data roaming is off by default. Turning on Data roaming will allow the device to attach to foreign wireless network signals when available. International roaming charges will apply. This setting does not apply to voice access, which requires additional provisioning for usage on international networks. To learn more, visit the AT&T International website.
To set whether cellular data is used for specific apps and services, scroll down then tap the Switch to the right of the Desired app.