Performance evaluation of WDM-PON RSOA based solutions in NGAN scenario

Starting from traditional access networks, Next Generation Networks (NGN) is the evolution of telecommunication infrastructures, from backbone up to access segment, able to support the growth of Internet and allow more performance in delivery of services as Triple Play, HDTV and ultra-broadband. Operators and Regulators are particularly focused on the technological changes needed in the access segment so called “last mile”. The last mile is the network segment, usually built with copper cables, that support broadband services by means of ADSL. It represents the bottleneck in the scenario of Next Generation Access Networks (NGAN) for the physical limitations of copper in terms of bandwidth and distances. The modernization of access network requires a massive replacement of copper with fibre optical cables. The problems concerned with this process are the investments for infrastructures and the sharing of the transmission resources (in physical unbundling or in bitstream). In this context two different network topologies are possible: point-to-point and point-to-multipoint. Among the different network topologies, the Passive Optical Network (PON) is an access technology where no other active device is installed between the network termination, in the home, and the central office. The target of this work have been the characterization of GPON transmission performances in comparison with an alternative solution based on Wavelength Division Multiplexing (WDM-PON) that seems to have more performances than GPON in terms of bandwidth allocation, scalability and capability of unbundling. We have realized simulations and deployed, in lab desk, a R-SOA WDM-PON test plant in order to evaluate the performances. The use of AWG and RSOA overcomes the traditional limitation of PONs in terms of bandwidth, flexibility and scalability with the prospective of unbundling based on wavelength allocation.