GPS (Developed by USA. The project that was kicked off following launching of the first satellite in 1978 could only be completed by 1994 with the number of satellites reaching 24.)
GLONASS (Developed by Russia. The project that was kicked off following launching of the first satellite in 1979 could only be completed by 2011 with the number of satellites reaching 24.)
GALILEO (The project that was initiated by the European Space Agency, ESA, in 1999 will incorporate 30 satellites in total and will be available to civil use by 2019.)
COMPASS-BEIDOU-2 (Developed by China. The system is essentially based on the COMPASS-BEIDOU-1 system, which was put in mission in 2000 with 3 satellites. The system will become functional in 2020 with 35 satellites.
IRNSS (The project was started in 2006 following its approval by the Indian government. The system was designed as a local positioning system and was inaugurated in 2016 with a total of 9 satellites.)