A self-tuning resonator for use in a transmitter apparatus for inducing alternating currents in a buried conductor. In this way, a scanning functionality may be implemented which prevents execution of the file before scanning is complete. The client device can include a module for determining the location of the client device at the time of purchase and include the location information with information used to complete the purchase of the product. The base station assigns each selected terminal with a time-frequency allocation, which may be for a wideband pilot, a narrowband pilot, or some other type of pilot.