generic term for all units used in a BPL-network
NOTES: The BPL infrastructure in a low voltage grid (230/400V) contains BPL-Headends, BPL-Repeater und BPL-Gateways. The BPL-Headend is the central unit of each BPL cell and the main gateway for the data communication between the BPL-network and the IP-Backbone (e.g. Ethernet). In every node of the grid (e.g. street cabinet or transformer station) whithout a headend a BPL-Repeater is installed to build up a meshed BPL-network. The BPL Gateways are the gateways to the meters installed in the buildings.