Mobile data drains your battery faster than wireless Internet does, so it pays to turn it off or use your WiFi network where possible. — dpa
If you use your smartphone a lot, you'll want to get as much out of its battery as possible, and relying on wireless Internet instead of mobile network can help. For many purposes, accessing the Internet via WiFi requires less power than doing so through LTE or 3G.
Many mobile phone service providers are already offering WiFi calling. The upside: It saves battery power and improves call quality when you're inside a building.
iPhone users can enable WiFi calling in their "Phone" settings. Android users will find the option in the advanced wireless settings. However, not every Android device supports this feature.
Depending on the provider, you may also have to add this option to your plan first. — dpa
