Akefa,
That’s a good one 🙂 The timing advance does not depend on the speed of the mobile !! It is a measure of the real distance between MS and BTS, by using the delay in propagation. The speed of a EM wave is 300.000km/h. A car moving a 300km/h would not change a thing here…
Ghost RACH are usually an effect of hardware distubances, or maybe fluctuations of EM in the atmosphere ?? Anyway, the ghost RACH contains dummy information, and the TA of a ghost RACH is “unrealistic”.