Apple is going to make it much easier to use your iPhone when you have bad cell service
Now, with its newest beta (i.e. an unfinished version of the software meant for trial purposes), Apple has introduced two small but useful features that are designed to help your iPhone maintain a secure Internet connection even when cell service is poor.
The fifth beta for iOS 9 adds Wi-Fi calling and Wi-Fi assist, which Apple blog 9to5Mac first noticed. Wi-Fi calling, as its name implies, allows you to make calls over a Wi-Fi network rather than a cellular connection.
In the current beta of iOS 9 it only seems to be available via T-Mobile and AT&T, but it's possible that Wi-Fi calling will be available for more carriers when the software officially launches this fall (we've reached out to Apple for clarity on this and will update accordingly when we hear back).
This means that if you're in an area where cell reception is very limited but your phone is connected to a better-performing Wi-Fi network, you'll have the option to make the call over Wi-Fi. It's a useful addition if you happen to be in a city or neighborhood where your carrier's service is particularly slow or unreliable.
iOS 9 will also bring another new feature to the iPhone called Wi-Fi Assist. This enables your iPhone to intelligently switch between using a cellular connection or Wi-Fi depending on which service is performing faster.
Currently, your iPhone automatically uses Wi-Fi for tasks such as browsing the web if Wi-Fi is turned on and you already have a connection set up in your phone. You have to turn off Wi-Fi to switch over to cellular, but soon enough your iPhone will do this for you if your Wi-Fi network is too slow.
iOS 9 will come to iPhones and iPads this fall, and it will focus on improving security, stability, and enhancing Apple's core apps. The most notable additions include a revamped Siri that's more contextual, and updates to apps such as Notes and Apple Maps among others.