Hi, everybody!
Today I will explain “How to choose an optical cable?”. During the design phase, this is one of the very important steps.
Based on the user's request for the realization of a certain link/network, we choose a certain transmission medium. It can be only one medium (e.g. only optical cable), but most often it is a combination of at least two transmission media (e.g. optical cables and coaxial cables). In general, today no telecommunications network does not have an optical transmission medium. Because of that, I will explain choosing optical cables.
Figure 1. Optical cable
(https://www.ofsoptics.com/optical-fiber-coatings/)
The next step is a type of optical fiber. We choose the type of optical cable based on users' needs (length of the optical link, required services, and bandwidth, etc.).
There are two types of optical fiber – multimode and single-mode fibers.
Figure 2. Multimode and Single-mode fibers
(http://www.fiberopticshare.com/single-mode-fiber-vs-multimode-fiber-choose-2.html)
Multimode fibers are mainly used for indoor installation or outdoor installation for a short distance of up to several kilometers. Multimode fibers are used when there is a dust problem because multimode fibers have a bigger core (62.5 or 50 microns) than single-mode fibers (8-10 microns). The light source of multimode fibers is LED or VCSEL at 850nm or 1310nm.
Singlemode fibers are mainly used for outdoor installation, from a few meters to a few hundred kilometers. It has unlimited bandwidth and offers "unlimited possibilities". Singlemode fibers use FB or DFB laser diodes.
The next step is determining the route of the optical link. Design is done on multiple substrates, mostly drawing is done in AutoCAD. It is useful for one of the substrates to be a satellite image like Google Maps.
Once the optical cable route is determined, it is necessary to go and view that route. It often happens that it is impossible to realize certain parts of the route. This requires relocation, choosing a more convenient route. Because of that, it is very important to view each part of the route design.
Figure 3. Direct Burying Cable By Plowing It In
(https://www.fiberinstrumentsales.com/blogs/placing-fiber-optic-cable-aerial-vs-underground.html)
After that, we have a definite route and we can correct the project. Based on the defined routes and based on the laws and regulations of the state, city, and municipality through which the route passes, we can define the types of optical cables.
Some states, cities, or municipalities do not allow any installation of new cables. They have laid pipes or optical cables, and rent pipes or fibers. On the other hand, new installations are possible in some places, but not above ground but only underground installations are allowed.
Based on geography and applicable laws, the optical route may be only above ground, or only underground and underwater, or it may be a combination of above-ground and underground and underwater installation. Based on that, we can determine which optical cables we need.
Thank you!
