A technique is provided for a direct data transfer session, including for multimedia content, between mobile devices without the need for using a separate multimedia server to store multimedia content. Then a group III nitride compound semiconductor represented by a general formula AlxGayIn1-x-yN is laminated thereon. The graded-stoichiometry insulating tunnel-barrier layer includes graded stoichiometry to compensate for thickness profile and thereby produce a uniform tunnel-barrier resistance across the structure. In addition, coolant is prevented from flowing from the water jacket on one side of the cylinders, across the bore bridge, and into the water jacket on the other side of the cylinders. The logic is further configured to classify the bounding region based on the prioritization performed by the logic. The layer is characterized by a strong growth texture, measured using XRD, and by the almost total absence, , and diffraction peaks.