Evolution Path: GPON to NG-PON2
After GPON Recommendations were done, FSAN and ITU-T continued the study of NG-PONs and defined the first phase of NG-PONs as systems that offer low costs, large capacity, wide coverage, full service, and interoperability with existing technology. FSAN and ITU-T members also agree that long term PON evolution will be driven by new scenarios if coexistence with legacy systems is not required. In addition to time-division multiplexing (TDM) PONs, other technologies for NG-PON could also be taken into account.
The key to a successful upgrade is to make sure that no changes are required to the optical distribution network. This requires the operator to place a coexistence element (CE) in the central office, and to make sure the current GPON ONTs/ONUs are equipped with the WDM filters as described in ITU-T G.984.5.
The evolution to a NG-PON2 network can be performed by inserting a NG-PON2 blade at the optical line terminal (OLT) and routing the fibres to the coexistence element (CE). Figure following: Coexistence of GPON and NG-PON2
What is NG-PON2
NG-PON2 (Next-Generation Passive Optical Network 2) is a 2015 telecommunications network standard for a passive optical network (PON). The standard was developed by ITU and details an architecture capable of total network throughout of 40 Gbps, corresponding to up to 10 Gbps symmetric upstream/downstream speeds available at each subscriber.
A passive optical network is a last mile, fibre-to-the-x telecommunications network that broadcasts data through fibre optic cables. PONs are managed by passive optics such as unpowered splitters and filters, offering high reliability and low cost compared to active networks. The PON data stream is generally converted to a more traditional service such as Ethernet and Wi-Fi at the subscriber’s location.
NG-PON2 is compatible with existing PON fibre by replacing optical line terminal (OLT) at the central office, and the optical network unit (ONU) near each end-user.