A clear trend is emerging in the form of fixed and mobile telephony convergence (FMC). The aim is to provide both services with a single phone, which could switch between networks ad hoc. Several industry standardization activities have been completed in this area such as the Voice call continuity (VCC) specifications defined by the 3GPP.

Typically, these services rely on Dual Mode Handsets, where the customers' mobile terminal can support both the wide-area (cellular) access and the local-area technology (for VoIP). Historically (see below) DECT and Bluetooth have been used locally, although there is a clear trend towards WiFi and in the future, WiMax. Implementations of Voice call continuity claim "seamless mobility between VoWiFi and cellular networks" and on mobile handsets are designed using a software voice engine.

One example of this convergence is the BT Fusion offer in UK, where British Telecom offers a Vodafone handset capable of making calls through the ADSL line via a local wireless connection (in trials and early launch this was bluetooth but the product is now transitioning to using WiFi). Another example is Divitas networks, which offers mobile to mobile convergence (MMC) technology for dual mode handsets, a different approach that uses VoWLAN as the primary means for voice communication while in WiFi areas, routing the calls exclusively through internet protocol to other locations and thereby relying less on the carriers for the voice traffic. The cellular service engages once the WiFi signal deteriorates sufficiently, to provide coverage outside of the WiFi area.

Other examples are provided in France with WiFi connectivity around the base station, by the BeautifulPhone from Neuf Cegetel by the means of a QTek 8300 or Home Zone from Wanadoo with a Nokia handset. Free (French ISP) develops a wifi mesh network of HD freeboxes to be used to provide mobile telephony and compete with traditional cellular operators.