Service provider AirSatOne said it has “certified its network for compatibility with Wi-Fi calling," and that smartphones capable of Wi-Fi calling can be used for telephone calls and texting during all phases of flight on business jets equipped with Internet-capable satcom systems. According to AirSatOne president Jo Kremsreiter, “With Wi-Fi calling, when the mobile phone loses cellular coverage but Wi-Fi is available, it automatically switches to Wi-Fi for calls and text messages, allowing the phone to work the same as it does every day on the ground. Testing of Wi-Fi calling over AirSatOne systems has revealed extremely clear voice and virtually no background noise.”

The Wi-Fi calling feature on many modern smartphones uses Adaptive Multi-Rate Wideband (AMR-WB), “which is an audio codec with compression optimized for speech coding,” according to Kremsreiter. The user does not need to install a third-party application, and the phone uses the same cellular number for Wi-Fi calling and texting, he explained, with full use of other features such as call waiting and multi-party calling, all at no extra charge beyond the normal satcom service fees. 

Inmarsat SwiftBroadband systems have plenty of bandwidth to handle Wi-Fi calling, he said. “The satcom system must be Internet-capable. Iridium does not have the bandwidth. Basically, passengers and flight crew can receive calls and place calls anywhere their aircraft is located in the world, at 45,000 feet and even over remote oceanic regions. If someone calls their cell number, it will ring in the aircraft. The most important thing is this is ‘baked in’ to smartphones now so the application is fully integrated, which means it is seamless and people using it won’t have to do anything to make it work [after they have activated it]. In the air it will automatically switch and calls keep coming in.”