This paper presents a new approach to upgrade and
extend the reach of the current passive optical network (PON) by
using wavelength division multiplexing (WDM) in the standardized
optical grid of gigabit PON (In-band WDM PON overlay). The aim
is to increase the number of optical distribution networks (ODNs)
fed by a single fiber while preserving the users bandwidth. In this
approach four downstream (DS) wavelength signals are
transmitted from an optical line terminal (OLT) to four different
ODNs using the standard DS PON spectrum ranging from 1480 to
1500 nm. The upstream (US) signals from the four different ODNs
are also wavelength multiplexed within the standardized US PON
spectrum ranging from 1270 to 1330 nm. Experimental proofs of
concept are presented in a 20 km PON serving 32 ONTs and in a 58
km extended PON in order to demonstrate the feasibility of this
proposal.
