PON vs AON – What’s the difference?

Monday Minute

There is a lot of discussion around which fiber network architecture to adopt for your fiber network deployment. At its core, a rugged fiber network strategy is a best practice that should be a part of every company’s day-to-day operation. The two most common fiber technologies are PON (passive optical networks) and AON (active optical networks).

What exactly are the differences between PON and AON? To get a better understanding, let’s take a closer look to see which one can help you achieve the desired performance for your network.

PON vs AON - What’s the difference?

PON (Passive Optical Networks)

A PON is a point to multipoint network structure where passive optical splitters are adopted to separate and collect optical signals. The fiber optic splitters permit the PON network to serve multiple customers in a single optical fiber without the need to deploy individual fibers. As a result, each user will have an optical networking unit (ONU) at the point where the fiber terminates.

When working with a PON, it’s important to note that optical splitting the fiber is at the foundation of the network. More specifically, it will require splitters that are bi-directional with fiber signals being sent downstream from a central hub. Conversely, signals from the user can be sent upstream and combined into one fiber to allow communication with a central office.


AON (Active Optical Networks)

In contrast, an AON is point-to-point (P2P), meaning that each customer has its own dedicated fiber optic line which is terminated on an optical concentrator. In an active optical system, electrically powered switching equipment (i.e., a router or switch aggregator) are used to manage signal distributions and direction signals to specific customers. Additionally, a switch directs incoming and outgoing signals to a dedicated place by opening and closing in numerous ways. AON’s are ideal for high-profit end customer segments, such as businesses, multi-dwellings, universities, and local authorities.

So, what type of technology should you use? The short answer is that no one technology can be applied for all cases. An AON is typically used for large distances up to 90 km whereas passive optical networks are often used in smaller distance residential areas up to 20 km. Both systems provide feasible solutions and are growing in popularity. When planning between a PON or an AON, it is critical to consider what services will be delivered over the network, the overall method typology, network planning & design software, and the primary customer.


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