A pivot assembly that can be retrofitted to existing traffic poles. The IC comprises a main processing unit and a non-volatile memory hardware block which may be programmed for permanently storing a start-up code executable by the main processing unit to allow the device to boot-up. The thickness of the upper metal layer is chosen to be 10 nm or more. Time differential is measured by autocorrelation of the entire impulse radio scan period, by detecting the leading edges of both incoming signals or various combinations of these methods. The shortest path tree includes all data transmission routes in the tree except links leading from a spoke to a hub. Step is to laminate stacking the anode current collection board, at least a membrane electrode assembly and the cathode current collection board from top to bottom to manufacture a single-piece structure, and thereby an anticorrosive bipolar fuel cell board is fabricated.