Warning: mobile data consumption is higher by 9 iOS feature WLAN wiz. Tonight Apple released the iOS update 9. Also on board of the new Apple operating system is an interesting feature, which is enabled by default after the update: WLAN wiz. With this new feature Apple iOS 9 applied, even when an existing Wi-Fi connection, the wireless network when the Wi-Fi performance is poor. So Apple describes the "Settings - Mobile network" hidden at the very end WLAN switch Assist as follows:

"WLAN Assist: automatically use mobile data case of bad wireless connections"

Actually, this is an excellent new iOS 9 function. If the wireless network in which you are registered, not "good enough" to work, then the iPhone or iPad instead uses the mobile Internet connection via the SIM card. However, this feature may well also provide a significantly higher consumption of mobile data volumes, since this volume is naturally settled on the mobile phone contract. 

So who has to get a mobile phone contract with a small monthly data volume, so you should be particularly careful here. Because even if your iPhone you still indicates the connection to the WLAN, this new feature could ensure that your entire monthly data volume is consumed by a few Youtube videos.

So if you use an iPhone with a mobile phone contract, which brings only a small volume of data included, you should therefore consider to exclude corresponding apps from the mobile data usage, or simply disable WLAN wiz completely.

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