This disclosure is directed to methods, computer-readable media, and systems for controlling one or more uninhabited heterogeneous autonomous transport devices. Layers corresponding to the plurality of channels are displayed along the time base in such a manner that width of each layer is determined in accordance with the number of sub-carriers used for each channel at any given time. Portions of a plug may be removed during the wet etch to form overhanging spacers to provide further protection of the conductor during the dry etch. Such a design not only can fully utilize the heat-absorbing space on the roof and save the cost for being displayed in marketing channels, but also can be constructed by the users in accordance with their own needs, so as to save cost in modularization.