Deployment case studies of an energy efficient protected LR-PON architecture

Current DSL products that provide broadband over copper pair are reaching their capacity limits. In many cases, their peak rate struggle to deliver HDTV video streams, which are widely acknowledged as one of the killer Internet applications in the near future. Fibre-to-the-premises (FTTP) solutions are being deployed to address the problem of scarce capacity in the network access. However, their ability to increase access capacity by over two orders of magnitude could create substantial scalability problems as power consumption of current IP-centric network architectures in the metro and core nodes will scale linearly (or worse) with capacity increase. Long-reach passive optical networks were introduced as a solution to this scalability problem, since they considerably reduce cost and power consumption for network operators, by allowing optical bypass of a large number of metro nodes in the network. In this paper we report the results of a deployment study of a dual-parented protected, nation-wide LR-PON installation for Ireland and the UK, based on real dataset. We focus on further reducing the overall network power consumption by employing a protection mechanism that reduces the IP router capacity required for protection as well as the number of backup OLTs. We show that in a realistic LR-PON deployment up to a 40% reduction in power consumption can be achieved, compared to solutions adopting legacy 1+1 protection. This is accomplished by optimising the network deployment for energy efficient protection, and adopting a smart load balancing technique and a core node architecture that allows N:M protection of backup links.