With its tenth satellite in orbit, Beidou, the Chinese equivalent to GPS, is "operational." China plans six more satellite launches before the end of 2012 and a total of 35 by 2020.
If the translation is accurate, Chinese officials are unclear on how the systems works.
Beidou now offered location, timing and navigation data to China and surrounding areas announced the project's spokesman Ran Cheng.
The interface control document is available in English (pdf).