dissociate GPS positionning from network based positionning. The developer chooses which one to use.
set DesiredAccuracy to be Default. Use PositionAccuracy as Default and it will do the best positioning possible.
In wp7 you have the choice b/w activating or diactivating location altogether. If GPS which very power consuming compared to Cell based positionning is disabled I want my application to still be able to get the position from celle based postionning