An apparatus, and an associated method, for powering a powerline network apparatus, such as a HOMEPLUG™ transceiver. A data signal sensor is positioned to sense a data signal that is to be operated upon by the powerline network apparatus. When a data signal is sensed, an indication is formed, and the indication is used to control the switch positioning of a switch that interconnects a power supply with the powerline network apparatus. When the indication of sensing of the data signal is formed, the switch is closed, and the power supply is connected to the powerline-network apparatus operative power is provided to power the powerline network apparatus.