A home gateway 30, input devices, output devices and a client are connected via a network LAN. The maintenance effort for the flow meter is reduced by there being at least one photovoltaic cell on the housing in a manner configured and arranged surrounding the at least one display device. All other chains and stumps are optimized randomly assigning to a stump a chain that can be physically reached by that stump and adding an additional chain to that stump based on the number of latches in the additional chain, its physical location, and the number of latches already assigned. The second terminal connected to the physical quantity measurement unit. Important entity attributes from the structured content and the entity neighborhood in the graph are automatically summarized as the entity fingerprint.