In free space, two frames A and B are at rest with respect to each other. They each flash light signals toward the other at an equal and constant rate. (i.e. on for one second, off for one second) Each then begins to move toward the other at a significant constant speed. ••••• Assumption 1••••• They cannot determine the equality of their motion in the equality of the (doppler shifted) frequency of the light signals measured by both. Although it is reasonable to assume their procedure to acquire equal motion is verified in their measurements, they can only agree their tests measure "relative" motion between them. ••••• Assumption 2••••• Each now measures the (doppler shifted) frequency of the others light signals increased proportional their relative speed. ••••• Question 1••••• Does the time dilation of either frame affect the frequency of light signals measured by the other?