Can mobile positioning technology be used as global positioning or is it only useful for local services?

Yes, Ericsson's MPS can be used for Global Positioning. If positioning is to be used within several mobile networks, the mobile operators involved need to have the same version of an Ericsson MPS in their mobile network, and there has to be a roaming agreement between the operators. The technique that Ericsson offers with MPS can most certainly be an alternative to the traditional GPS. For more information look into the System Overview part for Mobile Positioning on the Ericsson Mobility World website.