The high-level design of an FTTx network

Step 2: designing your network

Once the what, where and when of your FTTx network rollout plans are decided upon, it is time for stage two, making high-level network designs. Here, complexity increases as the network designer composes the network layout for a specific area. During this process, he or she needs to respect the network architecture rules and local limitations.

Ideally the network layout should avoid civil works as much as possible. And it should maximally reuse existing infrastructure such as ducts, poles, manholes and cabinets. This makes network deployment more cost effective.

Greenfields versus brownfields

Designing brownfield projects poses different challenges than designing greenfield projects. In greenfield projects, the designer has many design options. He or she will decide where new trenching or boring needs to be done, or just to follow the road network.

You can limit the deployment cost for brownfield projects by reusing existing infrastructure. But things become complicated as you need to consider the infrastructure’s limitations.

The sum of these small, detailed and critical tasks makes this stage a time and effort intensive process. At the end of this stage, the designer will have to come up with a feasible and futureproof network design. And he or she needs to deliver a detailed bill of materials to order the needed network equipment. The margin of error is slim as wrong decisions can prove to be expensive and time-wasting.

Detailed input is key

The designer needs much more detailed input data compared to the previous stage. Geographic information of streets, buildings (containing home counts) and existing infrastructure are all required. The quality of the design heavily depends on the quality of this data. That is why companies invest a lot of time and money in acquiring high quality data.

To end up with a good design, the designer needs to make structural decisions for the chosen area. Where to put network elements such as the central office, fiber concentration points and other nodes. Or which cable routes should be used to serve feeders and distribution points. And all this while you need to make sure that at least one fiber is delivered to the home from a central office through various intermediate routes.

To make sure these decisions are feasible, validation in the field is needed. During these inspections, changes may arise which trigger a network redesign. Changing the location of distribution cabinets or modifying distribution or drop reach, may trigger a redesign of the whole area or at least a part of it. Consequently, designers end up designing the whole area multiple times.

Automated software as a helpful tool

As this is highly inefficient, automated software helps to improve this process. Making it less tedious and costly. This software automatically performs pre-processing steps, applies network constraints and generates an interactive geographical network. The software automatically routes cables and ducts, places equipment and generates the bill of materials.

It provides the freedom to work on multiple areas at the same time. This way you have the time to make important decisions, rather than to get stuck in monotonous tasks such as drawing cables and ducts.

a fiber network design

It can also integrate manual changes made by the user and recalculate the whole network within a short amount of time. This gives the user full control, it provides the opportunity to thoroughly cut costs, and to design the optimal fiber optic network for every area.