System design of reverse-powered G.fast

The continued growth of multimedia traffic pushes access network operators to further boost performance over their copper infrastructure network. As a result, digital subscriber line technology has evolved substantially. Field and lab trials have proven that recent innovations, such as crosstalk cancellation and phantom mode transmission, can push data rates of VDSL2 higher than 100 Mb/s on a single twisted pair and 300 Mb/s on two pairs. In ITU-T Q4, a new access technology to provide aggregate data rates in the range of 500 Mb/s to 1 Gb/s per copper loop of up to a few hundred meters is being defined under the G.fast project. G.fast enables the continued cost-effective deployment of fiber in the access network. In this paper, we give an overview of some key challenges this new access technology needs to overcome. By taking into account the expected access network topology, we give guidelines for the node architecture and deployment of G.fast.