Different satellite navigation systems

Currently four major economic power blocs have their satellite navigation systems, either fully operational or in process of being so. These systems are used for military and civilian purposes both. Here are four systems:

1. GPS - US government-run satellite navigation systems. Global Positioning System (GPS).
2. Beidou - China's own GPS. It offers location, timing and navigation data to China and surrounding areas. China has 10 setellites at the moment and plan to have 35 by 2020 to cover entire world.
3. Glonass - Russia's satellite navigation systems
4. Galileo - EU's satellite navigation systems. First satellite was launched in Oct 2011, planned to be fully operational by 2019