While I agree that 95% of folks out there have either and IOS or Android device that they carry, it just may not be the ideal use model for WLAN voice over IP (VoIP) in healthcare.
Learned a few things years ago when at Symbol about mobile radio performance via the WLAN. Not all WLAN radio chipsets or modules were designed for a highly mobile environment where you had to maintain a very secure enterprise connection while in motion and roaming from AP to AP. The roaming algorithms determine a lot. Having Wi-Fi Alliance approval does dictate actual performance, it is more about interoperability.
Smart Phones were primarily designed for cellular use, with the after thought of putting in a WLAN radio. Think of the early on issues with one manufacture and the internal antenna placement.
Another aspect of using consumer devices for a voice over IP connection is also about power longevity of the device. This depends on the device when the WLAN radio is on and dependent upon using either PSP or CWA modes. In CWA the current drain is fairly extensive and having to change batteries or re-charge during a shift is pretty much not acceptable.
While there are cases that protect impacts; any device should at least be rated for
IP-56.
