We are using passive PoE injectors and long ethernet cables. 


Below a reference table for the voltages ranges of the hardware we use:
||= '''Item''' =||= '''Low''' =||= '''High''' =||
|| alix2d13 || 7V || 20V ||
|| NS2 || 9V || 24V ||
|| Bullet2 || 10V || 24V ||
|| airCam || 9V || 24V ||