Unlicensed Mobile Access (UMA) cell phones support GSM and Wi-Fi

New Unlicensed Mobile Access (or UMA) cell phones from manufacturers such as Motorola, Nokia and Sony Ericsson are expected to deliver connectivity to both the traditional cell phone infrastructure (through GSM) and to VOIP services through Wi-Fi. However, its yet to be seen whether such functionality will provide competition and lower rates for consumers or whether these devices will be sucked up through exclusive deals by the dominant cell phone companies in the North American market, with the VOIP functionality tied to their networks. In other words, they’ll automatically switch to the cell phone operator’s VOIP service when used inside the home or in the office where cellular connectivity may be weak but where a strong wi-fi signal may be available, but won’t necessarily offer lower rates for such usage. To get the best of both worlds, I suspect early adopters will still need to carry two phones.