Consider the following scenarios. On a Windows 8 computer, if you have a Mobile Broadband connection available, and if you keep switching the Airplane mode between On and Off quickly, randomly the Mobile Broadband connection might still be off even after the airplane mode has been turned off. After that, this mobile broadband connection will be kept in the Off mode until you turn it on manually.
This is by design for the WWAN Radio Manager in Windows 8 and it can be triggered when all of the following conditions are true.
1. When you turn on the airplane mode, Windows will send a Radio Off command to the device.
2. The device doesn't complete the Radio Off command in 5 seconds.
3. You turn off the airplane mode before the device finishes the first Radio Off command.
4. After the device finishes the first Radio Off command, you turn on the Airplane mode again.
If all of the conditions are true, the issue will be triggered.
If the problem happens, please follow the steps below to turn on the Mobile Broadband connection manually.
1. Open the Charm bar, and click Settings.
2. Click Change PC Settings.
3. Click Wireless and we can find the option to turn on the mobile broadband connection.
Windows 8 Hardware Certificate program requires a mobile broadband device to finish the Radio On/Off command within 5 seconds, and if the device can meet this requirement, the problem won't happen. If the device doesn’t complete the Radio Off command in 5 seconds while the user keeps switching the Airplane Mode settings at that time, Windows cannot keep waiting because it will cause undesired problems on user interface, and prevent the other wireless network connections from being changed.