A PoE system includes a plurality of PoE devices and a hub that are coupled in a ring configuration through a plurality of network cables. The hub is coupled to two of the network cables, and provides electric power to at least one of the network cables that is coupled to the hub. Each of the PoE devices is coupled to two of the network cables, receives electric power from one of the two network cables, and supplies electric power to the other one of the two network cables. As a consequence, each of the PoE devices can be directly or indirectly powered by the hub.