Optical fibers are being used more and more in the access network for delivering ultra-high speed broadband services to customers. From the pure technological point-of-view, Fiber-to-the-Home (FTTH) is the ultimate solution for delivering broadband services to customers thanks to the inherent advantages of fiber, which include high bandwidth capacity, low power loss, high reliability and immunity to interference.
Nevertheless, when a taking a decision which technology to deploy, a service provider must also consider the practical aspects and the financial ones. In locations with existing infrastructure and high density of population, deploying fiber to every customer's house or apartment is not practical due to the need to upgrade the infrastructure inside buildings or in busy streets.
The new G.fast technology is intended to address this need by introducing the Fiber-to-the-Distribution-Point (FTTdp) topology, in which the copper complements the fiber in the very last section of the network. With FTTdp, fiber is deployed up to the building or to the distribution cabinet which is close to the subscriber, but the existing copper infrastructure remains in use from that point and on. G.fast can deliver up to 2 Gbit/s over copper loops of up to 250 meters, and thus allows service providers to offer "fiber-like" throughput to their subscribers.
There are several other characteristics of the Distribution Point Unit (DPU) which are defined in the G.fast technology specifications. These include Reverse Power Feeding (RPF) to allow the DPU to be fed over the copper wires from the customer side, as well as new models for management of the DPU.