How to Select the Right Multimode Optical Fibre Cable

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How Do You Choose Fibre Optic Cable?

The volume of data transmitted across corporate networks has surged dramatically in recent years. As technology has become integral to business operations, investments in IT infrastructure have grown at a similar pace. Optical MultiMode Fibre and Singlemode Fibre have played a key role in supporting this evolution.

Technological advancements like desktop virtualisation and unified communication tools have placed additional demands on networks, making robust and reliable data cabling more critical than ever. In this ecosystem, the choice of data cabling significantly impacts the performance experienced by end users.

IT cabling—whether copper or fibre—evolves alongside advancements in hardware. For this reason, selecting the appropriate cabling is essential to ensure a well-rounded and future-proof IT solution.

Which Fibre Optic Cable Should You Use?

When choosing fibre optic cable, consider the following key factors:

    1. Technology Requirementsimage of fibre optic cable end
      What devices, systems, or applications need to be connected via fibre optic cabling?
    2. Transmission Speed
      What speed is required to meet your organisation’s current and future needs?
    3. Distance Between Endpoints
      How far is the distance between the transmitting and receiving equipment?
      Singlemode fibre is ideal for long distances, while MultiMode fibre is better suited for shorter spans.
    4. Installation Environment
      Will the cabling run entirely indoors, or will it include outdoor sections?
      If outdoors, what risks could affect the cable, such as exposure to rodents or damage from machinery?
    5. Budget
      What is your budget for the project, and how does it align with the required specifications?

By carefully evaluating these factors, you can select the most suitable fibre optic cabling for your business needs.


Choosing the correct fibre optic cabling 

Understanding the importance of your cabling choices is essential. Selecting the right fibre optic cable ensures optimal performance from your IT infrastructure, providing users with fast and reliable access to the vast amounts of data they require. This, in turn, maximises workforce productivity and operational efficiency.

Conversely, neglecting network cabling can lead to subpar performance, ultimately undermining investments made in other areas of your IT systems.

To simplify the selection process, the international standard ISO 11801 defines four primary classes of MultiMode optical fibre cables. These are categorised based on modal bandwidth, offering clear guidance for identifying the most suitable cabling for your needs.

Making the right choice is critical to ensuring the seamless operation of your technology, supporting the demands of both current and future applications.

OM1 – 62.5µm core; 200 MHz-km @ 850nm

  • OM2 – 50µm; 500 MHz-km @ 850nm
  • OM3 – 50µm; 1500 MHz-km @ 850nm
  • OM4 – 50µm; 3500 MHz-km @ 850nm

For this purpose differing bandwidths of these cables allow high network speeds to be maintained over longer transmission distances.

Optical Multimode Fibre Comparison Chart

Category

Minimum modal bandwidth
850 nm / 1310 nm[10]

100 Mb Ethernet 100BASE-FX

1 Gb (1000 Mb) Ethernet 1000BASE-SX

10 Gb Ethernet 10GBASE-SR

40 Gb Ethernet

100 Gb Ethernet
OM1 (62.5/125) 200 / 500 MHz·km up to 2000 meters (FX)[11] 275 meters (SX)[11] 33 meters (SR)[11] Not supported Not supported
OM2 (50/125) 500 / – MHz·km up to 2000 meters (FX)[11] 550 meters (SX)[2] 82 meters (SR)[2] Not supported Not supported
OM3 (50/125) *Laser Optimized* 1500 / 2000 MHz·km up to 2000 meters (FX) 550 meters (SX) 300 meters (SR)[11] 100 meters[2]330 meters QSFP+ eSR4[12] 100 meters[2]
OM4 (50/125) *Laser Optimized* 3500 / 4700 MHz·km up to 2000 meters (FX) 1000 meters (SX)[2] 400 meters (SR)[13] 150 meters[2]550 meters QSFP+ eSR4[12] 150 meters[2]

 

Fibre Optic Cable Comparison

For instance, the industry standard minimum reach for OM3 cable at 10 Gbit/s speed is 300m. However. while OM1 is capable of supporting similar speeds, this only holds true over short distances. OM4  however can maintain it over an even longer distance (550m).

OM1 is therefore more widely used at the slower speed of 1 Gbit/s. For this reason, it supports a transmission reach of 275m. Thus, OM1 is pretty much phased out in modern technology requirements.

In the past, people were generally content with the 1 Gbit/s speeds that were possible with OM1. However, in more and more cases this is no longer sufficient.

Therefore, in our experience working with a range of clients, we are finding more people wanting to upgrade from OM1 to the laser-optimized OM3. Thus facilitating faster network speeds and greater bandwidth.

Fibre Cable Performance vs. Distance vs. Cost

Therefore, the decision to which optical multi-mode cable to choose ultimately comes down to a question of performance, requirements, distance and cost.

Generally, the ISO 11801 classifications have greatly simplified this decision making process. To begin with, by defining an industry minimum standard reach for varying levels of performance.

Therefore, OM3  and Om4 are becoming the norm to achieve a 10 Gbit/s network. Subsequently, this is suitable if you require consistently high speeds to support a range of IP based technologies across your site.

Optical MultiMode Fibre Summary

In conclusion, if you are unsure which cabling solution is right for you, NM Cabling offers a free network survey. Furthermore, this includes expert advice on your options for installing, upgrading or growing your existing network.

Similarly, this document can be viewed as a PDF file Simplifying the Selection of Optical Multi-Mode Fibre

Accordingly, for  more information on Fibre Optic Cabling Contact NM Cabling  01923 888588 or see our page on Fibre Optic Cabling Installations

NM Cabling is a technology and structured cabling integrator working throughout the United Kingdom.

We have created a comprehensive Knowledge Centre for our industry which can be viewed at https://www.nmcabling.co.uk/knowledge-centre/