A signal transfer circuit in a pre-drive circuit converts the reference potential of a control signal, supplied from a drive control circuit, to the reference potential of an output element. The vacuum pressure is applied to the seed disk assembly by pulling a vacuum airflow through a collector of a spindle-mounted hub support that is fluidly connected through a face seal arrangement with a hub face of the seed disk assembly. According to various implementations of the invention, when the mobile message is received by the carrier network the mobile message is scanned for a URL. The receiving end is provided with a demultiplexer which demultiplexes the signal received from the common traffic channel back into separate information flows.