There is an intense pressure from OTT players on telecom operators, eating into their revenues. They turned operators into utility pipes but there is nothing brutal than eating their core voice revenues with Voice over OTT such as Skype. According to Telegeography, skype voice minutes increased from 6bn to 55bn minutes from 2005 to 2013, while international voice traffic decreased from 37bn to 35bn minutes in the past 8 years. The difference of 20bn minutes amounts to at least $200m of lost revenue with conservative estimate.
In order to fight back, operators have started launching Voice over WiFi, which allows seamless calling over WiFi without having to use any OTT app. This is a win-win situation as the customers get cheaper calls, especially when they travel internationally, but for CSPs when customers use WiFi indoors, reducing operator burden to improve costly indoor coverage and saving CAPEX and OPEX. Of course, operators have to upgrade their packet core to IMS to enable VoWiFi calling. But I think there is a clear business case of CAPEX and OPEX savings even after including the IMS upgrade costs.
However, VoWiFi is similar to best effort service as it goes over packet network. It is similar to VoLTE already launched by many operators. But VoLTE delivers poor quality especially indoors due to high attenuation of LTE high frequency signals indoors. But in order to encourage customers to use Voice over WiGi, and ensure they continue to use Voice over WiFi, operators have to ensure good voice quality over their WiFi as well as seamless handover experience between VoWifi and ViLTE. It would involve monitoring S2a and S2b interfaces and creating a service model that can track voice Key quality indicators. It also makes sense to take actual customer feedback on voice quality (similar to what Skype does when they ask you to rate call at the end of each call) and correlate that to KQIs to further tune. If ePGW is made part of IMS core, probe costs can be saved, making a cost effective monitoring. Per session voice capability monitoring is key to debug any voice quality experience issues and take corrective action.
:Lastly, it is important to communicate advantages of Voice over WiFi in simple terms to customers and encourage them to use it. Instructions on Locating and enabling Wifi calling on handsets should be made available across all contact channels and customer service should be educated to inform the customer on any inbound call.
Many US operators have already enabled Voice of WiFi calling and it remains to be seen how much usage is shifted to voice over Wifi and how much CAPEX and OPEX it has saved to operators and most importantly, how is the customer experience.