HT202639: Connect to Wi-Fi on your iPhone, iPad, or iPod touch

Learn about Connect to Wi-Fi on your iPhone, iPad, or iPod touch
Mark2768
Level 1 (0 points)

Q: Wifi vs Cellular Data Usage (Duplication)

When WiFi is connect do I need to turn off Cellular Data? Telstra (Australia's largest Telco) claim that whilst left on any data I use over Wifi is also double counted as Cellular data against my plan allocation - net result zero Cell data (all WiFi) usage but 86% plan usage (860mb) in first 2 days of plan period!

iPhone 5s, iOS 8.1.2

Posted on Jan 5, 2015 6:16 PM

by Lawrence Finch,Solvedanswer
Lawrence Finch Lawrence Finch
Level 8 (38,039 points)
Mac OS X
A:

When WiFi is connected the phone will use some cellular data, but very little - only for things that must go through the carrier, like Visual Voicemail, MMS messages or notifications. It is not duplicated data, however. But the key is "WiFi connected". If the phone goes to sleep WiFi is turned off unless the phone is connected to power, so if you have background processes running that use data they will use cellular data rather than WiFi when the phone is asleep.

Posted on Jan 5, 2015 6:21 PM

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Mark2768

Q: Wifi vs Cellular Data Usage (Duplication)

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  • by Lawrence Finch,Solvedanswer

    Lawrence Finch Lawrence Finch Jan 5, 2015 6:21 PM in response to Mark2768
    Level 8 (38,039 points)
    Mac OS X
    Jan 5, 2015 6:21 PM in response to Mark2768

    When WiFi is connected the phone will use some cellular data, but very little - only for things that must go through the carrier, like Visual Voicemail, MMS messages or notifications. It is not duplicated data, however. But the key is "WiFi connected". If the phone goes to sleep WiFi is turned off unless the phone is connected to power, so if you have background processes running that use data they will use cellular data rather than WiFi when the phone is asleep.

  • by Mark2768,

    Mark2768 Mark2768 Jan 5, 2015 6:25 PM in response to Lawrence Finch
    Level 1 (0 points)
    Jan 5, 2015 6:25 PM in response to Lawrence Finch

    Thank you Lawrence. That confirms that as I suspected the agent at Telstra was yet another poorly trained incompetent individual. Their records (not mine) show zero data downloaded over 3G/4G but 86% plan usage, she would not accept any "fault" other than with Cellular Data left on it means any WiFi usage is also counted as Cellular Data usage.