Information
The device can be configured to participate in Wi-Fi networks. It is recommended that Wi-Fi be disabled when not needed or where security is paramount.
If Wi-Fi is turned off on a device with cellular data service, connections to the Internet will occur via the cellular data network, when available. Applications such as the built-in Android browser, Gmail, Google Voice, Maps, News & Weather, and the Android Market can be run over a cellular data network connection, but there may be a limit on the maximum download size of items for certain apps.
Solution
On the Android device,
1. Press the Menu button.
2. Tap System settings.
3. Tap Wireless & networks.
4. Tap More.
5. Tap Wi-Fi.
6. Slide the Wi-Fi switch to the Off position.