The value of fiber for mobile network transport is undisputed: The enormous capacity and speed that fiber can enable is unmatched. But as operators bend ever more of their financial and operational resources toward deploying 5G networks, they may be overlooking an existing fiber resource that can be leveraged for mobile transport: Passive optical networks, or PON.
During the deployment of LTE, residential fiber-to-the-home networks were not as widely available as they are now. MNOs relied on dedicated fiber to connect cellular sites and provide backhaul for growing mobile traffic. This was an expensive, point-to-point solution that was nonetheless purpose-built for cellular backhaul, with economics that worked because of the lower density of sites required for low- and mid-band LTE deployments.
With the proliferation of PON and fiber-to-the-home, network operators have another option: Using a passive optical network as a cost-effective, high-capacity, high-speed platform that serves both wired broadband and mobile transport needs. PON offers reduced cost and faster time to market, both of which are critical to 5G deployment right now. PON is frequently deployed in the very urban and suburban areas where MNOs want to extend their 5G networks and compete for network switchers. The point-to-multi-point nature of PON provides better footprint and more attractive economics for placing small cells. For converged operators, leveraging PON may simply be a matter of making sure that their wired and wireless teams in each region are fully aware of available owned resources and that deployment processes don’t default to dedicated fiber lines. But PON has a compelling business case for wireless-only players, too: It is widely available and a less expensive alternative to point-to-point fiber or microwave transport. PON provides simpler deployment processes as well. The equipment for connection is small – less than 6 inches long – and plugs directly into a cell site with no additional space or power needed. Pre-configuring and validation work can be done ahead of installation to prepare the network for small cells, so that once the optical equipment is plugged in, the service is active.
PON offers all the needed capacity to carry both residential and mobile network traffic. Nokia, for instance, has Broadband Anyhaul solutions with PON capacity of 10 and 25 Gb/s. But what about latency and other quality of service concerns in a shared network? Passive optical networks, it must be acknowledged, were built to meet the demands of consumer internet traffic, not mission-critical mobile backhaul. However, there are new transport interfaces – some of which are based on Open RAN – and standards features that enable PON to meet the strict requirements of 5G, now and in the future. 5G edge computing deployments will further extend PON’s ability to support mobile transport capacity needs in the future as 5G traffic grows, by taking on local processing to meet low-latency requirements.
Within PON, there are multiple deployment options to ensure that shared passive optical networks meet mobile operators’ needs: Dedicated PON, which is optimized for 5G transport and benefits from PON’s cost efficiency; shared PON, in which fibers can be shared but the traffic is separated to ensure appropriate QOS; and sliced PON, which applies the principles of 5G network slicing to wired networks for service assurance. Which one is right for your 5G deployment? Learn more from Nokia resources here: Accelerate into Gigabit with fiber and Broadband Anyhaul
