The same channel has been reused in neighboring prefectures to efficiently utilize limited frequencies in terrestrial digital broadcastings. Therefore, it is important to understand the over-reach propagation of the same channel TV waves. In this study, we measured Received Signal Strength Indication (RSSI) and Carrier to Noise Ratio (CNR) of TV waves to quantitatively evaluate the over-reach propagation. We also measured RSSI of FM radio waves to identify which station transmitted the over-reach TV wave. 5-month measurement results indicated that there were CNR fluctuations depending on the over-reach propagation of TV wave. And the source of the TV wave was identified by fluctuations of one of the measured FM radio wave.