Power is assumed, yes, but it deals with physical media directly. That's what 1 is. You make or design the RF level hardware. Layer 2 is where PHY is a separate

Power is assumed, yes, but it deals with physical media directly. That's what 1 is. You make or design the RF level hardware. Layer 2 is where PHY is a separate entity - driver stack starts at the lowest point of this. (Used to be higher but now more things are offloaded to firmware or hardware.)