Deployment of FTTCab with remote powering and future evolution towards FTTdp with reverse powering

Telecom Italia, within its UltraBroadBand (UBB) development strategy, has the goal to deploy by the end of 2014 more than 25.000 “Fiber To The Cabinet” (FTTCab) nodes in all the main cities in Italy, hosting small Optical Network Units (ONU) with 48 VDSL2 ports each. Such particular architecture enables several benefits among which the possibility to use the existing primary copper network to remotely power the BB equipment from Central Office, thanks to the limited amount of power needed by the UBB equipment. This brings to the consideration that the Telecom Italia FTTCab with remote power deployment is one of the widest ever performed worldwide. This paper will firstly provide information on power consumption evolution of the UBB ONUs, highlighting the good path followed by the equipment towards greater energy efficiency. The activities towards Standardization Bodies, in particular ETSI and ITU-T, as well as European Commission (with the Code of Conduct on BroadBand equipment) will also be mentioned. The paper will then describe the associated evolution of the remote powering architectures massively adopted by Telecom Italia for its FTTCab deployment since 2012, highlighting their pros and cons. The different solutions adopted at the Main Distribution Frame and at the cabinet in order to guarantee proper protection to the technicians against discharge current will also be described. Moreover, the paper will provide an overview of the evolution of the FTTCab towards more “compact” solutions for both ONUs and remote power modules, reducing the overall physical footprint (and the total power consumption) and enabling underground and pole installations. Finally, the paper will describe the evolution of the FTTCab architecture towards the “Fiber To The distribution point” (FTTdp) architecture, involving even smaller UBB ONUs (1 to 8 lines) with even higher throughputs thanks to VDSL2 and G. Fast technologies applied to s- orter loops. This will enable the shift from “remote powering” to “reverse powering” paradigm; to this end, the main features and challenges related to the latter solution will be highlighted.