Digital Terrestrial Television Service Area (Digital Terrestrial Television Service Area) monitoring system by the Office of the Broadcasting Commission Television and Telecommunications (Office of the NBTC) aims to help people find directions in receiving digital television signals. Based on the propagation model together with the network operator's technical data, only in the main station. And relying on topographical data to calculate. All data are analyzed by software which is a prediction. and reserves any liability that may occur whether directly or indirectly resulting from the use of this information in all cases, the Office of the NBTC shall not be liable for any damages.