An Extension of the Link Layer Discovery Protocol for On-Demand Power Supply Network by PoE

We focus on Power over Ethernet (PoE), which is the technology to carry power on LAN cables, and extend LLDP (Link Layer Discovery Protocol), in which power requests are sent in PoE, so that power is supplied on demand. In on-Demand Power Supply Networks, Powered Devices (PD) are classified by their priority. When a device requires power, it sends a power request message, in which required power and the priority of it is specified, to the network. Then the network decides whether to accept the power request or not. In this paper, we argue on the implementation of on-demand power supply based on PoE, present a lack of features in LLDP, and propose two extensions of it within an approved options of the IEEE standard. The first one is that a PD can send a request PSE (Power Source Equipment) specifying the priority of required power as well as it. The second one is that the PSE can reply back information when a request from a PD is not accepted.