This invention is directed to a security system for wireless access points which includes a clamp assembly and a locking device. The power-feeding radiation electrode is used to perform antenna operation in a basic mode in which resonant operation is performed at a basic frequency and antenna operation in a high-order mode in which resonant operation is performed at a frequency higher than the basic frequency. The latch circuits temporarily hold data read out from the memory cell array. The system can also add additional strategies such as a termination strategy if a vehicle brake is applied. The determined price is then stored in a memory of the apparatus and displayed for customers.