Active Ethernet eliminates the need for power blisters (ac-to-dc converters) and 110/220 V AC cabling installation. With Active Ethernet, system installers need to run only a single Ethernet cable instead of separate power and data cables to each Access Point base station. The Active Ethernet solution consists of a power injector, typically installed in the wiring closet, that injects the DC power onto the Ethernet cable. The Active Ethernet unit constantly checks the Ethernet cable for a device that can handle PoE. If it does not detect such a device, Active Ethernet switches off power for that port. This power-monitoring capability protects other devices connected to the Ethernet cable with power as well as the input port of the switch in case of an installation error.