Power Allocation Algorithms of PoE for on-Demand Power Supply

An on-demand power supply network is proposed in i-Energy project as a method to achieve the goal of powersaving in home. In the on-demand power supply network, power requests of devices are classified by priority of Quality of Life. When each device requires power, the device sends a power request message which contains required power and the priority to the network. When the network accepts a request message, the network supplies power to the device. In this paper, we focus on Power over Ethernet(PoE), in which power requests are sent from PD(Power Device) to the PSE(Power Supply Equipment) by Link Layer Discovery Protocol and Physical Layer. However PSE cannot allocate power for several PDs according to priority. We propose fair power allocation algorithms in terms of the priority from PSE to PD for minimizing decrease of QoL. We measured power requests and allocations time of PDs by using real PoE equipment. We show allocation time to complete the process within a certain period of time even in the worst case, that is, many devices send power request messages at the same time.