UMA stands for Universal Mobile Access and it’s the technology that allows your phone to switch between networks seamlessly. You’ll notice this technology when your phone switches between WiFi and cell tower. The above figure shows how UMA works and it also describes one of the benefits of UMA which is better coverage via WiFi. Your mobile device will use WiFi to send a signal through the Internet back to the carrier, and thus using the hotspot to boost coverage. This isn’t the best part of UMA though. It will actually save you money.
When a phone is using UMA to connect to the carrier through WiFi, you carrier loses the ability to track your location. Think about the possibilities of duping your carrier into thinking you’re somewhere you’re not. By connecting via WiFi, you can avoid roaming charges, which range from $1 a minute to $5 a minute. Some carriers such as T-Mobile offer a $10 per month charge that gives you unlimited calls via WiFi. This means that you can reduce your minute plans and call almost entirely on WiFi thus making your phone similar to a VoIP device.
So when you’re buying a device, consider a UMA device because it will save you lots of cash. Here are some UMA devices on the market today: