What is left in fibre access bandwidth?

In this paper, the impact of the evolution and successive compatibility requirements between different legacy technologies in optical access fibre is assessed. Various relevant factors will be summarized, as they have been elsewhere discussed, and the limitations stemming from each mapped. The considered stringing factors can be mainly grouped in: fibre inherent impairments, standards and technologic and investment trends. The result of this paper will be a summarized vision on the conditions and scenarios for further usage of the existing bandwidth and which could be the actions for improving it.