New Link Layer Discovery Protocol (LLDP) TLVs (type, length, and values) are defined for negotiating system level energy-efficiency parameters [14].
negotiating
LLDP power negotiation allows the PoE controller to dynamically allocate power to LLDP-enabled powered devices based on their power needs. The PoE controller allocates to an interface only the power currently required by the connected powered device, and it can allocate the power in small increments. (LLDP was defined in the IEEE 802.1ab standard initially released in 2005 and revised in 2009.)