Seamless switching between cellular and local networks for mobile users. The goal is to have a handset that switches automatically from the cellular network to the local, wireless Wi-Fi network when entering a building in order to save cellphone minutes.

Expected in the future, there are several challenges with fixed mobile convergence (FMC). The handset has to support TDM technology for the cellular system and switch instantly to packet-based voice over IP (VoIP) for the Wi-Fi network. In addition, roaming between wireless access points within a campus or enterprise is problematic. See dual-mode handset.