Selecting a fiber optic cable according to distances

It’s a well-known fact that fiber optics is the way most of the IT infrastructure service companies currently transmit information. It makes sense if you bear in mind that it allows information and data to travel at greater speeds, through greater distances, and in never-before-seen bundles.

Fiber optics also allows these companies to be insured against the future in terms of bandwidth. The amount of data that travels through these conduits is massive and it will only increase through time. Making sure your networks can endure the load now and in years to come is one of the many perks of fiber optics.

Electrical interference of any kind doesn’t faze fiber optics either, making it the best choice for networks that are data-sensitive and handle security issues. This also gives it an extra ounce of reliability which relieves a lot of the worry in terms of maintenance and upkeep.

Choosing the proper fiber optic cable to fit your needs may seem like a daunting task but it really isn’t. Just invest some time to do the necessary research beforehand and you´ll save yourself a lot of time and trouble as well as money.

For Starters,

If you are looking to perfect and/or enhance the build-out of your network through fiber optics, start by doing an in-depth assessment of your current and future needs. Knowing for sure how your networks will be used and for what is essential for this evaluation since it will allow you to properly and accurately select the type of fiber you might need depending on the application.

For example, let's say you are looking to upgrade the backbone of your network you will more than likely need a cable which differs completely from what you might need if you are looking to install security and surveillance cameras in a given location.

Some other points to consider when selecting the fiber optic solution that best fits your needs are:

  • Distances of transmission: you must be fully cognizant of the distances that the information you will handle must travel. This is crucial in determining what type of cable best suits you.

  • Current and future bandwidth requirements: consider the amount and type of data and information that will cruise through these cables. Nobody wants a slow network, right?

  • Network architecture: the way your entire network (hardware, software, communication and connectivity protocols and modes of transmission) is laid out should be taken into consideration when selecting your fiber optics.


Fiber optic cables are the wisest choice over copper cables which have been traditionally used until recently. It can most definitely support many further distances of input travel than its metal counterpart but the exact distance is difficult to determine as it is limited by a plurality of factors.

This is a vital issue for optical communications since it prides itself in being super-fast (as it indeed is) putting data transmission distance under the spotlight.

The signal transmitting the information from point A to point B may possibly weaken if the distance is very long. There are many methods that can be applied and components that can be used to diminish the limitations inflicted by optical transmission distance.



Basically, the amount of data or information that can be transmitted through a cable in a fixed or given amount of time is called bandwidth. If it’s referring to a website, for example, bandwidth determines the quantity of information and the level of traffic that can transfer between the site, its users, and the Internet as a whole which is why web hosting companies are prone to offer maximum levels of bandwidth as part of their hosting packages. 

 What to look for?

Fast connections and great company CRM that offer the best-in-class of terms of networks, connections, and systems. It stands to reason that the more width of a band that the company can provide, the faster and more efficient your network or site will be in those three categories.

In the digital realm, bandwidth is commonly expressed in bits per second (bps) or bytes per second. Don´t mistake one for the other, though. Both are units used to measure information storage amounts and both have very similar acronyms (Mb and MB) but there is a big difference that can have major repercussions on your network‘s performance levels: one byte is made up of 8 bits.


In terms of data transmission, the distance it can travel decreases proportionally to any bandwidth increase and it’s measured in Hertz (Hz).

While bits and bytes determine the amount of data that given devices can storage, a Hertz is a unit of frequency that can indicate how often an action is done. If something is said to be 120 Hertz then that something has a repetition frequency of 120 times in one second.

When dealing with fiber optics, here’s more or less how it works: a fiber cable that can support 800 MHz bandwidth throughout a distance of 1 kilometer will only be able to support 400 MHz at 2 kilometers and 200 MHz at 5 kilometers.

Types of Fiber Optic Cables

There are two types of well–known optical fiber cables and each has their own set of unique qualities and characteristics: single-mode and multi-mode.

Before we continue, let’s clarify what dispersion is: it is basically the spreading over time of the signal that carries the data through the cables.

There’s chromatic dispersion in which the signal spreads over time due to the action of different speeds of light rays and there’s modal dispersion, in which case the signal is spread out through time as a consequence of the different modes of propagation used in the optic fiber.

Single mode optical fiber usually has an 8.3-micron diameter core and makes use of laser technology and light to send and receive data. A micron is a unit of measure equal to 1 millionth of a meter. So you can picture it: one strand of human hair has a diameter of more or less 100 microns.

So single mode fibers have the ability to carry information for miles without losing too many data which makes it ideal for companies that offer services such as cable and telephone providers.

Transmission distance is affected by chromatic dispersion because the core of single-mode fibers is much smaller than that of multimode fibers. And it is also the reason why single-mode fiber can have longer transmission distance than multimode fiber. 


High powered lasers operating within single mode optical fibers lend it its efficiency since they can readily transmit data at far greater distances than the light used in their multimode counterparts.

If you need to handle large amounts of data with the least dispersion, single mode fiber might be your best choice. Just take into consideration that these fibers are noticeably more expensive than multimode ones since the technology used is a bit more sophisticated.


Multimode optical fiber, as its very name indicates, allows the signal to travel through different pathways or modes that are placed inside of the cable’s core. For these types of fibers, the transmission distance is largely affected by modal dispersion.


Due to the fact that the fibers in multimode cables have imperfections, the optical signals are not able to arrive at the same time causing a delay between the fastest traveling modes and the slowest ones, which in turn causes the dispersion and limits multimode fiber performance.

This type of fiber uses inexpensive LED (light emitting diode) light sources to transmit data. The signal travels through an LED-based optical transmitter called a media converter, then down the glass in the fiber and bounces from wall to wall within the cable until it reaches its final destination at a rate of 10 or 100 Mb/sec but all that bouncing brings modal dispersion to the mix, diminishing the amount of data transmitted over a specific distance.

The demand for more data and faster reception of it has increased over the years making LED cables seem terribly slow and limited. This caused the creation of cables that use lasers to transmit data along with light, giving the world single mode optic fibers.

Multimode fibers can be found in 4 different presentations identified with the acronym OM which stands for optical multi-mode and varies according to performance criteria determined by ISO/IEC 11801 standards. These presentations are OM1, OM2, OM3, and OM4.

If you want to know more about these different multimode fibers, be sure to check out our blog entry on the subject:

September 30, 2016 by
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