In a YouTube video , Telekom network economist Gordon Witzel explains the concept: Access points connected with the data network via a fiberglass cable within the mast are installed at the head of the street light. The access point broadcasts in the 60 GHz range on four channels, each with 2 GHz of bandwidth, and so achieves data transmission rates of 1 Gbit, split for upload and download.
To catch the signal, a special all-round antenna must be mounted outside a window with a line of sight to an access point no farther than 100 m away. The customer’s antenna is connected to a standard Telekom router via an Ethernet ribbon cable, for example through the rubber window sealing. The access points can contact each other in bridge operation and forward the signal.
Obstacles, nevertheless, remain. Currently an access point can feed no more than 16 customers, which will increase to 30 later. The connection also depends on the weather, as heavy rain for example can dampen down on transmission rates. Another problem is that street lights are generally connected in series and supplied with power only when it’s dark. Telekom would either have to change the power connection or install a battery to serve as a buffer during the day. The 60 GHz band solution is currently ultimately approved for in-house operation only; external operation is expected over the course of the year.