GLONASS is GPS, works to the same standards as the original GPS. The original was launched, supported and maintained by the USAF, primarily for military use. It later on was opened up to commercial use, but with reduced accuracy (plus or minus 15 meters). Now it's open to all at a much higher accuracy (plus or minus a couple of meters), although not to the full accuracy used for military targeting and some scientific measurements (millimeters). GLONASS was the Russian version, but uses the same frequencies and standards so GLONASS and the USAF system are compatible and cooperative. GPS is a generic term for Global Positioning System, and generally applies to both systems. So, for the OP, GPS works the same in Europe as it does in North America, or anywhere else on the planet, for that matter.