By Rob Anderson, EnerSys
Cable operators worldwide are deploying passive optical networks (PON), realizing high-capacity, low latency performance with low maintenance costs. Although PONs are essentially passive, current architectures make use of outside plant (OSP) active optical components. Strand- or pedestal-mounted remote optical line terminals (R-OLT) can replace rack mounted OLTs of a few years ago. When fiber runs extend beyond optical transceivers’ effective range, midspan erbium doped fiber amplifiers (EDFA) boost optical levels and extend fiber reach. Evolving PON architectures are designed to support higher speeds and extended service areas. Next-generation PON implementations will likely include high speed coherent optic links from headends to new OSP aggregation nodes, enabling even faster services to extend deeper into the network. Each active optical component in our PON architecture requires reliable, uninterrupted power to keep the network running.
This paper reviews aspects of powering the OSP active components of modern PONs including power levels, utility grid isolation, utility backup duration and power system status monitoring. Unique requirements for powering expanded rural fiber networks are discussed as well as considerations for addressing an aging utility grid and the impact of extended outages. Roles and methods for power monitoring and remote management are discussed as well as the need for predictive and restorative maintenance.