To improve the throughput performance of HF-PLC systems, a dual-mode transmission system, which utilizes the mode diversity of differential and common modes, has been studied by the authors. However, the system which uses the common-mode has a risk to cause the unintentional radiation problem. To solve the problem, an Adaptive power control method to the Electromagnetic Environment, which is called AEE, has been proposed. The radiation detection was achieved by receiving emitted PLC signals at affected (or concerned) devices. In this paper, a new detection method and a new mode-selection method have been proposed, and it is shown that their preliminary results are attractive from the viewpoint of usefulness. ? 2011 IEEE.