A wireless communication method for providing zone boundary detection performed by a controller managing communications within a multicastbroadcast service zone. The outer foil can be a one-piece slush-molded foil or it can be highly stretchable and a thin thermoplastic bonding foil can be provided between the outer foil and the core layer. One end of an impedance adjusting circuit is connected to a connection node between the outputs of the first and second amplifier devices, the other end of the impedance adjusting circuit is connected to one end of a second switch circuit, and the other end of the second switch circuit is connected to a ground potential.