Unlicensed mobile access (UMA) technology is an application that provides users of both global system for mobile communications (GSM) mobile services and general packet radio service (GPRS) mobile services with alternative access, such as Wi-Fi® and Bluetooth®. It serves the need for people to stay connected, and is a good alternative for cellular phone users when there is no GSM or GPRS service. When these services are not available, UMA phones will look for unlicensed access points for Wi-Fi® and Bluetooth®. This capability adds to the reliability for a mobile device to stay connected to the network.
Wi-Fi® is widely used for providing Internet access to personal computers (PCs) and laptops at homes and in most commercial places. There are voice and short message service (SMS)-equivalent services that are available on the Internet. Bluetooth® is a popular short-range wireless communication medium with increasing features. It is commonly used for extending accessories such as headsets, microphones, and cameras. New features are being released to increase the usefulness of Bluetooth®.
UMA computers may be primarily linked via Wi-Fi® or Bluetooth®. When these services are not available, the UMA computer may look for GSM or GPRS service as a fallback. This scheme could be very affordable if Wi-Fi® and Bluetooth® access is available most of the time. For example, a user who travels to an area where GSM coverage is not available may be able to access Internet or Wi-Fi® service in that area. In theory, with UMA technology the user will be able to make calls with the Wi-Fi® infrastructure.
The goal of UMA technology advocates is the seamless integration between GSM, GPRS, Wi-Fi®, and Bluetooth®. This means that the network controllers for the GSM and GPRS will be communicating with Wi-Fi® and Bluetooth® network controllers. In theory, a mobile UMA phone may be handed over from GSM/GPRS to Wi-Fi®/Bluetooth® and vice versa, all without interrupting the call.
UMA technology may ultimately provide better overall service for all users. If a dual phone can be programmed with personal preferences, such as rules in registering and affiliating to GSM, GPRS, Wi-Fi®, or Bluetooth®, then the users will benefit. The day will come when people could all be using UMA technology or its equivalent, and they may not need to know which mobile system they are actually using.