iOS: Understanding cellular data networks
Summary
This article provides information on GSM, CDMA, and LTE cellular data networks.
Products Affected
iPad (Wi-Fi + Cellular models), iPhone
When a Wi-Fi network is unavailable, iPhone and iPad (Wi-Fi + Cellular models) are capable of using a cellular data network for Internet connectivity.
Select your carrier network technology to learn more about the cellular data network capabilities and features, including:
- Network types
- Status Bar icons
- Whether simultaneous voice and data are supported (on iPhone)
GSM networks
GSM networks support simultaneous voice and data on iPhone when using a UMTS connection.
Cellular network | Status icon | Simultaneous voice/data |
Notes |
UMTS | 4G | Yes | Appears on iPhone 4S and iPad (3rd generation) Wi-Fi + Cellular with iOS 5.1 while connected to AT&T's high-speed network in the United States. |
UMTS | 3G | Yes | |
EDGE | E | No | May be unable to receive calls while transferring data over the cellular network.* |
GPRS | ° | No | |
* If you cannot receive the call, it will immediately go to voicemail. |
CDMA networks
CDMA networks do not support simultaneous voice and data on iPhone
Cellular network | Status icon | Simultaneous voice/data |
Notes |
EV-DO | 3G | No | Can receive calls while transferring data over the cellular network. |
1xRTT | ° | No | May be unable to receive calls while transferring data over the cellular network.* |
* If you cannot receive the call, it will immediately go to voicemail. |
LTE networks
LTE is available with supported LTE carriers.
Cellular network | Status icon | Simultaneous voice/LTE data |
Notes |
LTE | LTE | No1 | iPhone 5 and iPad (3rd generation) Wi-Fi + Cellular only.2 |
|
Additional Information
Cellular data requires an active phone or data plan with a wireless carrier. Contact your wireless carrier for more details.
Cellular data may not be available in all locations, and network speed and connectivity may vary depending on location. Check the carrier's network coverage in your area for availability. See this article for links for wireless carrier support and basic information about the features supported by wireless carriers.
When you are outside your carrier's network, you may be able to access the Internet using another wireless carrier. To use another carrier's network, turn on Data Roaming in Settings > General > Cellular for iPhone; on iPad useSettings > Cellular.
Notes:
- Roaming charges may apply, contact your wireless carrier for more information. To avoid data roaming charges, make sure Data Roaming is turned off.
- When using a cellular data network that does not support simultaneous voice and data, incoming or outgoing calls will interrupt cellular data transfers until the call ends. This does not affect Wi-Fi network connectivity.