Re: What happens if WiFi and 4G are turned on at the same time
It also depends on what network you use. If you're connected to Wi-Fi then your phone will use the Wi-Fi to send/receive data. It will still remain connected to your carriers data network in the event you need to send/receive MMS, but the connection to your carrier will remain dormant/inactive until it is needed. If you're with T-Mobile, your data connection will be on 3G until transfer is required and then it will switch to 4G if available. I believe on AT&T you remain connected to 4G all the time.
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