The cyclic prefix is intended to be long enough to encompass most significant multipath signals. Consider one of the LTE CP durations of 4.7 ms. Multipath delays come from signals traveling longer distances that the shortest path signal. If the shortest path between TX and RX is 1 km, what is the distance of the longest traveled multipath signal if the multipath delay should be much, much less (again using a factor of 10) than the CP duration? Assume signals travel at the speed of light.