The Smart, Connected Building | Corning

More and more businesses prefer optical fibre to copper networks given its benefits in enterprise environments. A passive optical network (PON) is a fibre optic network that does not require active components for signal distribution and replaces the aggregation electronics and associated copper cables in a traditional switch-based architecture with passive optical splitters and single-mode fibres (SMF). This creates an architecture that is lower in cost to purchase, install and maintain – and with a far longer life span – than traditional copper architectures.

Passive Optical LAN (POL) is the application of passive optical network (PON) technology in a local area network environment. There are four things to look for in passive optical networks. First, one must ensure splitter technology integrates seamlessly into the enterprise. Corning designed a POL solution specifically for local area networks. The optical splitters integrate directly into a wall-and rack-mountable hardware.

Second, one must choose optical splitters that are proven to be reliable. POL promised a long-term solution to meet future bandwidth requirements, without having to repeatedly replace the existing horizontal infrastructure, when it was first introduced almost ten years ago as a replacement for a traditional active Ethernet architecture. While PONs were originally created to provide fibre-to-the-home (FTTH) or fibre-to-the-premises (FTTP), their advantages soon became apparent in end-user access applications. Thus, there is a marked progression into the fibre-to-the-desktop solutions in use today.

Last, one must leverage band-insensitive fibre technology and match a chosen installation method to a building’s design requirements. POL can address many issues of today’s traditional network topology. POL is especially useful in enterprise environments, like office buildings and campuses, which require cabling system infrastructures with higher density and ongoing moves, additions, and changes.

POL was devised to best serve enterprise environments, and to recognize POL’s basic design and characteristics is essential to understanding its benefits for businesses. The topology is point-to-multipoint using single-mode fibre (SMF) as the cabling infrastructure, thus delivering the advantages of distance and density. The central component is an optical line terminal (OLT) that functions as a fibre aggregation switch and provides full Layer 2 functionality. The optical network terminals (ONTs) are edge devices that convert the SMF handoff to the copper-based connectivity required by the end-user devices

SMF cabling is thinner, lighter, more flexible, crush-resistant, and has a greater tensile strength than copper category cabling. Resistance to corrosion and to electromagnetic interference have made fibre optics the preferred cabling infrastructure in modern networks. There has been a clear progression in the use of SMF as a backhaul infrastructure to premises connectivity, vertical cabling applications, and even now the horizontal cabling solution. With all of these benefits, the single greatest attribute is its bandwidth capability, which has been described as limitless. SMF cabling used in today’s POLs has enough potential bandwidth to support the next five generation of LAN speeds. Furthermore, today’s SMF infrastructure has enough available capacity installed to support those speeds by simply changing network hardware.

The OLT and ONTs make up all active components. POL provides flexible mounting, powering, and Power over Ethernet (PoE) options. The ONT powering can be served with both local and remote powering options, including battery backup. The passive infrastructure compromises SMF, passive optical splitters, and the cable management accessories used to house the splitters and distribute the fibre. Splitters are the centerpiece of the passive portion of a POL and manufactured with numerous split and housing options.

The convergence of passive and active components into a turnkey solution differentiates POL from legacy point-to-point copper-based LAN. Fundamentally, POL moves the Ethernet edge out of a closet and closer to the end-user devices. This topology creates a large LAN footprint. In contrast to fibre-based LAN, due to performance characteristics of today’s copper category cabling, traditional copper-based LAN has a distance limitation of 100 meters. This limitation restricts deployment options as end-user devices must be placed within 100 meters of the nearest network switches or telecom closet.

There is stark difference between copper and fibre cabling. The use of SMF in a POL creates a LAN footprint of just 20 kilometers, and allows multistory buildings, multiple buildings, or even an entire campus to function as a LAN on just one OLT. This approach eliminates the need for aggregated network switches and privacy. In addition, this approach provides environmental support. POL reduces space requirements, overall cable load, telecom closet expenses such as power and cooling, and simplifies operation by centralizing LAN management.

In comparison with point-to-point copper-based LAN, there are extensive benefits derived from POL’s advantages, and they are diverse in their significance across several different vertical applications:

• The distance advantage of POL will reduce or eliminate most of the telecom closets including racks, grounding, cable trays, sleeves, fire stopping, among others. Doing away with closets and local switches frees up valuable space and creates a reduction in power consumption, natively and through the elimination of heating, ventilation and air condition (HVAC) or chillers.
• The density advantage of POL will provide multiple horizontal fibres from a single switch port, multiple ports from a single fibre-cable connection, and a 50-to-70 percent reduction in structured cabling. This translates to less stress load on the building and less footprint in plenum ceiling space.
• The security advantage of POL comes from SMF being a more-secure medium than copper cabling, and ONTs being inherently secure because they are designed with no local management access.
• The future-readiness advantage of using SMF as the structured cabling will provide a greater return on invest (ROI) on the initial capital investment as it extends the lifespan of the cable plant from 5-7 years to 25-plus years. Additionally, facilitating network upgrades by swapping edge electronics instead of ripping and/or replacing the cable plant eliminates the requirement for above-ceiling work.

A smart, connected building eschews traditional single-purpose networks for an intelligent and converged infrastructure. The benefits of a connected commercial building span from better space utilization and tenant satisfaction, to improved sustainability and lowered risk of repair, and even reduced capital expenditures and operational expenses. However, it is not the streamlined convenience of POL’s converged network capabilities that create benefits for businesses and spark future-forward outlooks. It is how POL adapts to meet future challenges that largely determine the rewards reaped by businesses. At its onset, POL came with a unique set of trials before it could deploy in an enterprise network. Powering was one such trial, solved by using remote powering solutions that make powering digital enterprise with POL a non-issue. POL must adapt to the future as technology continues to evolve and new platforms are enabled. Businesses must also respond to the challenges presented by demand – and therefore need – for widespread connectivity. Investing in quality fibre matters, it is the foundation that both sustains and connects modern businesses around the world.