Planning the Distribution Network. Part 2.

In reality, network topologies are rarely used in their pure form. The main reason is the wide variety of deployment conditions — you have to account for all sorts of factors in each specific situation: where buildings are located, distances between subscriber groups, total line length, and many more. For example, you might split the signal three ways at the start, then run a bus to two subscribers, followed by a 16-way splitter. There are countless combinations, and there's no one-size-fits-all solution.

Another factor is the expected take‑rate — the percentage of subscribers you plan to connect. For a group of buildings, one operator might reserve enough power for 100% of potential subscribers, another might plan for 50‑70%, and someone else might consider 20% or even 90% sufficient. The projected take‑rate depends on residents' income levels, the cost of connection, payback periods, competition, and existing infrastructure. In a monopoly situation, you can expect a high percentage; but if you're entering an area where another provider has been operating for a long time, you'll probably see much lower numbers.

For our own network, we decided to design for 100% take‑rate. The reasoning was simple: we wanted to build the entire network all the way to the subscriber tap points from the very beginning. That way, connecting a new customer would just mean running a pre‑made patch cord from the nearest splice closure — or making one on the spot using quick‑connect connectors. No additional work on the main fiber would be required. This means a regular field tech could handle the connection, without having to call in specialized fusion splicers.

If we had planned for a lower percentage, we'd run the risk of eventually running out of available taps in a particular area. That would force us to do extra work — splicing in additional fibers, replacing splitters, allocating more OLT ports, and so on. Of course, you can never be 100% sure that no new connection points will appear down the road. But planning for full coverage significantly reduces that risk. Chances are, we'll never actually reach 100% take‑rate — but if that happens, there's a nice upside: every connected subscriber gets more bandwidth available on both downstream and upstream.

This article is a translation of the original Russian-language post.My journey of learning GPON