A level shifter circuit has first to fourth transistors and a resistive element. Each replaceable feeder unit includes at least two feeders for supplying the printed sheets to the conveying device and an undercarriage. A relay physical downlink control channel is demodulated, by the RN, based on either the cell-specific reference signals or the UE-specific reference signals. The main body of the first pipe and the main body of the second pipe has an equal or almost equal outside diameter. Specifically, the inventive spiral-wound membrane module is designed having a corrugated entrance and exit spacers together over less than 10% of the length of the spiral wound module and a stiffener sheet wound to provide for uniform feed channel gap width.