A stacked chip assembly includes individual units having chips mounted on dielectric layers and traces on the dielectric layers interconnecting the contacts of the chips with terminals disposed in peripheral regions of the dielectric layers. The top end is used adjacent a ceiling. The semiconductor stacking unit has a configuration in which the semiconductor modules and coolers are stacked. The system then determines whether the rear-wheel steering should be provided based on a predetermined relationship between the sensed hitch angle, the equilibrium hitch angle and the pseudo-equilibrium hitch angle. In one embodiment, the login page may include a transkey and a value B. An OLT for a PON, comprising a downstream transmitter, and a plurality of upstream receivers, wherein a downstream transmitter bandwidth is greater than each upstream receiver bandwidth is also disclosed.