iPhone 6 Plus - VoLTE Compatibility
Posted by Wesley on
iPhone 6 Plus falling back to 3G for voice calls
Cellular communications have traditionally used separate voice and data channels. But with the advent of smartphones, bulk of the communications now happen on the data channel. It's no coincidence that only the data channel remained by the 4th generation (4G) technology. To carry voice, though, a fallback to 3G or older technology's voice channel was initially needed. But VoLTE (Voice over LTE) came onto the scene to do away with this by letting the data channel handle voice as well.
As with many technologies, Korea was a forerunner in adopting VoLTE. World's first commercial VoLTE service was launched more than two years ago by two of the three major Korean carriers, SK Telecom and LG U+. The remaining one, KT, joined mere two months later. Worldwide adoption didn't really take off until earlier this year, however. About a dozen carriers around the globe now have it. Noting this trend, Apple has decided to enable the capability in the iPhone 6 series.
So naturally, I wanted to see VoLTE on my iPhone 6 Plus in action. It can be enabled in the Settings app by going to Cellular and selecting "Voice and Data" option for LTE. The previous 5/5C/5S models simply have toggle switch for LTE instead, even with iOS 8.0 update. After that, I made voice calls to a lot of different lines, including a VoLTE-enabled phone on the same carrier. But every time, the connection indicator turned from LTE to 3G, showing that VoLTE wasn't working.
iPhone 6 Plus seen as "OMD Default Handset"
I checked to see how the network recognized my iPhone 6 Plus. It was being listed as an OMD Default Handset, the same name that my iPhone 5S was given when it was brought in from the US. In other words, a generic device that it doesn't recognize. Perhaps the network couldn't tell whether the device had a VoLTE capability, so it simply ignored its attempts. It was time to visit my carrier's branch office to get to the bottom of this.