Context: In December 2011, the system went into operation on a trial basis. It has started providing navigation, positioning and timing data to China and the neighbouring area for free from 27 December. During this trial run, Compass will offer positioning accuracy to within 25 meters, but the precision will improve as more satellites are launched. Upon the system's official launch, it pledged to offer general users positioning information accurate to the nearest 10 m, measure speeds within 0.2 m per second, and provide signals for clock synchronisation accurate to 0.02 microseconds.

Question: When did the Compass system begin operation on a trial bases?
Answer: December 2011

Question: When did the Compass system begin offering navigation, positioning and timing data to China and nearby locations?
Answer: 27 December

Question: What will improve the positioning accuracy of the Compass system?
Answer: as more satellites are launched

Question: Upon launching, the Compass system, what was the location accuracy promised to users?
Answer: accurate to the nearest 10 m

Question: Upon launching, the Compass system, what was the speed promised to users?
Answer: within 0.2 m per second

Question: During which month of 2013 did the system begin a trial operation?
Answer: Unanswerable

Question: In what year did the system finish its trial run?
Answer: Unanswerable

Question: The system began charging China and surrounding areas in what month?
Answer: Unanswerable

Question: During the trial period, within how many meters was the NSEW system's positioning accuracy?
Answer: Unanswerable

Question: After official launch, the system declined to offer customers positioning information accurate to the nearest what?
Answer: Unanswerable