I want to know the answer to the following question:
What are the ranging signals of the BeiDou system based on?
All the background I'm provided with is that "When all the currently planned GNSS systems are deployed, the users will benefit from the use of a total constellation of 75+ satellites, which will significantly improve all the aspects of positioning, especially availability of the signals in so-called urban canyons.". Is that enough to answer the question?