SoftBank 304HW User Manual page 179

Updating Software
In Main Menu, "Software Update"
"Continue"
Check the latest software. If software update is found, update software.
・ When software in use is the latest, "The latest version" appears.
Software Update
Packet communication charges are not applied for Software update.
While software is updated, other functions are disabled.
Software update is not available during International roaming.
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