Physical layer performance analysis of hybrid and stacked TDM–WDM 40G-PON for next generation PON

Current passive optical networks (PONs) (Gigabit PON (GPON) and Ethernet PON (EPON)) will run out of bandwidth sooner or later due to the ever increasing bandwidth demand. The aforementioned and the new next generation PON stage 1 (NG-PON1) standards (10 Gigabit-PON (XG-PON) and 10 Gigabit Ethernet-PON (10G-EPON)) are based on time division multiplexing (TDM-PON), which has its limitations such as limited bandwidth. In this paper, hybrid TDM–WDM PON and stacked TDM-PON architectures are evaluated and compared as solutions for NG-PON stage 2 (NG-PON2). Both architectures are fully capable of satisfying the requirements of NG-PON2. Stacked TDM-PON has the advantage of being compatible with the currently deployed optical distribution network (ODN). Considering four wavelengths and 10 Gb/s/wavelength, the hybrid TDM–WDM PON does not seem to offer noticeable advantages over stacked TDM-PON.