Estonian operator EMT said Wednesday that it has completed field trials of A-GPS technology embedded into the SIM card, allowing location based services (LBS) to be deployed to legacy handsets.

EMT has been testing technology from Luxembourg-based startup BlueSky Positioning, which embeds a GPS antenna and location based applications into the SIM card, allowing even 2G handsets to support LBS offerings.

The tests were conducted using both GPRS and the old school signalling channel USSD (Unstructured Supplementary Services Data) for retrieving assistance data in a live 3G network. Apparently, EMT is the first network operator to test a USSD connection for assistance data, meaning that A-GPS apps can be used with mobile phone models that do not even support GPRS.

The Estonian carrier still expects to carry out more tests on the technology, and has identified emergency assistance as the main opportunity, as required by E112 in the EU and E911 legislation in the US. However, EMT notes that there are a wealth of opportunities that can be offered by A-GPS SIM technology including generic LBS such as navigation, social networking, child tracking or more complex applications such as workforce and fleet management.

Argo Kivilo, R&D manager at EMT, said that the tests showed accuracy and time to first fix comparable with “any commercial A-GPS handsets in the market”.