For some reason I can't get it through my thick head whether or not the camera has to have power from the POE switch before it can be plugged into the powerline adapter to send the signal downstairs.
one port of the poe switch to the power line cable that then feeds back to the other power line near the router
then your poe switch assuming its 8 port with have room for seven cameras
then further down you can link another power line (up to sixteen) do the same with another poe switch and have another seven cameras