[Blake021]

I recently upgraded from my Curve 8900. The only
reason I switched to the 9780 was for the faster processor
and more memory plus 3G. The 9780 is great in all
areas except being a phone. It constantly drops calls
and can’t hold the uma connection. I need the uma
work and home to receive and place calls over wifi.
I upgraded to v6.0.0.285 and nothing has changed.
This may just be my particular phone, I haven’t seen
a post which mentions the same problems

[Dubdub]

Did you have the same problems with the 8900?

Maybe try to exchange for a new one.

[tsac]

Some carriers selectively offer UMA service depending on the location and service availability. T-Mobile and ATT both offer service but generally it is not to allow free phone calls. ATT offers a xxx8220;Femtoxxx8221; cell service that connects to your DSL service to allow you to xxx8220;forwardxxx8221; calls over WIFI but this service is not free also. Doing some reading I found T-Mobile does offer the service but it is generally not available without a plan and I suspect it is also limited to selective areas. T-mobile may have stopped the service in your area

Hope this helps

This is what UMA is supposed to be,
Unlicensed Mobile Access (UMA) provides access to cellular mobile voice and data services over unlicensed spectrum technologies, such as Bluetooth or Wi-Fi (802.11).

A UMA phone will use a cellular networks (GSM, CDMA, etc.) when out and about, and automatically switch to a UMA-enabled Bluetooth or Wi-Fi local network when in range, such as at home or in the office.

In local mode, a complete, virtual GSM or CDMA connection is "tunneled" to the carrier via the Bluetooth or Wi-Fi connection and the Internet. This allows seamless, transparent use of all services at all times, including voice, messaging, and data services.

This hybrid approach allows fulls mobility, while offering consumers better coverage, faster data rates, and lower service costs when using the local network.

The technology can also lower infrastructure costs for carriers, by reducing load on networks in densely populated areas, and reducing the need for towers in sparsely-populated residential areas.

[stewsan]

Actually, with T-mobile, I doubt the UMA service area is limited. I drive a big bus with retractable tires and use it at "bus stops" all over the world. For the past 3 years it's gotten more stable and useable. I've never found a location, after hooking up with wifi, that it doesn't work, even in China. I'd do the Batt pull and replace a few times and if that doesn't work, exchange. I didn't know ATT offered UMA, good to know!

[mikesta]

I've had the same issue with my 8900 and my 9780. I've opened numerous tickets with t-mobile. What works best for us is to set the phone to UMA only when at home or when using UMA. The downer is that you have to set it to 3G preferred when you leave or you won't get a call.

I've had much more success with this mode. Hope this helps.