VoWifi Overview

“Wi-Fi” is a trademark of the Wi-Fi Alliance and the brand name for products using WFA programs based on the IEEE 802.11 family of standards.

When I worked in R&D we used to say that patents are like hostages. The advantage is that we can create them ourselves.  In April 2009, 14 technology companies agreed to pay CSIRO (Commonwealth Scientific and Industrial Research Organization in Australia) $250 million for infringements on CSIRO Wi-Fi patents. Hence Australians labeled Wi-Fi as an Australian invention, though this has not been accepted by everyone without objections (especially in US). CSIRO won another $220 million settlement for Wi-Fi patent-infringements in 2012 with global companies in the US required to pay the CSIRO licensing rights estimated to be worth an additional $1 billion in royalties. Guglielmo Marconi or Joseph Fourier would be bambillionaires these days.

In our post the Wi-Fi refers to a WLAN access to ePC, both trusted over S2a interface or untrusted over S2b interface (3GPP TS 23.402). The VoWifi is then a voice and video over Wi-Fi IMS profile, defined in GSMA IR.51. If you are familiar with VoLTE (IR.92 and IR.94), the VoWiFi defines the same set of services, just over a different access network. The service network – the IMS – remains the same. Sure we need to be more sensitive when it comes to muli-device scenarios or access transfer.


This article is focused on the technical aspect of the VoWifi definition. Would you like to know a bit more about why to deploy the VoWifi, check out this post written by Alberto Diez.

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