Error detection section 109 carries out error detection using demodulated data and outputs an error rate to SIR versus error rate estimation section 110. Through holes extend along the fastener centerline through the conductive material and the underlying fuel tank shell. This dynamic threshold may be determined to ensure that at least a certain percentage of receiving nodes are potential branch nodes, based on the received signal strengths of those nodes at the root node. The first substrate and the second substrate are brought into contact and form bonded substrates, with the top surface of the first substrate facing the top surface of the second substrate. This allows ion implantation to be used to provide precise doping profiles advantageous for manufacturing solar cells.