Area Control Services

An aircraft is flying at FL 150 in class D airspace, while another aircraft at FL 140 has been cleared to descend to FL 70. Given the severe turbulence in the area, when can a clearance to descend to FL 140 or below be anticipated?

What is the minimum longitudinal separation required between aircraft that have departed from the same airport, are on the same flight path, and where the aircraft ahead is flying at a true airspeed that is 20 knots or more faster than the one behind?

What is the minimum longitudinal separation time between aircraft at the same cruising level, where navigation aids allow for frequent position and speed updates, and the preceding aircraft is flying at a true airspeed that is at least 40 knots faster than the following aircraft?