Fibre Optic Patch Cables, What to know when selecting

So, what do we need to know when choosing Fibre Optic Patch Cables?

Firstly, what we need to have for good optical performance in fibre optic patch cables are three primary characteristics:

– low loss

– minimal reflectance

– high mechanical strength

Fibre optic patch cables will come with loss results and these results will be listed on the packaging. They should be tested in both directions so there should be 4 test results for you for a duplex cable or 2 results for a simplex cable.

Comparing simplex to duplex fibre optic patch cables just means comparing the difference between one fibre or two fibre’s and therefore either only one connector at each end of fibre optic patch cables or two connectors at each end. Duplex fibre optic patch cables are the most common type as one fibre is typically used to transmit data signals and the other fibre is there to receive them. However, in some instances (bi-directional applications), only one fiber is required, so simplex fibre optic patch cable are all that is needed.

duplex patch cable

simplex patch cable

Why do we test in both directions, I hear you ask? 

Well, that is because the connector quality can differ at each end of fibre optic patch cables. You might have a connector with an extremely low loss on one end and one with a slightly higher loss on the other. Not each connector will be exactly the same or have the exact same loss as the other.

Why do we need to know the test results?

Having this information helps you to know that when you have finished the install that all the fibre optic patch cables you supplied at the time were within the required standards. Should there be a problem after the install you can easily go back to your documentation and check to see if something has changed to the performance of the fibre optic patch cables that you supplied. Helping you quickly and easily understand what and where the issues could be. Also, if you are working with a very strict loss budget these results become quite important for the overall performance of the network as well.

Secondly, what is your network environment?

You will need to know the transmission speed you wish your network to operate at. With so many options available this will need to be thought of very carefully. Typically, this is a cost driven decision that is made. 1G, 10G, 40G and 100G are common speeds used in the Ethernet environments with talk of 200G and 400G in the future.

Next, the distance your network needs to operate over will also dictate which products you may need to use. The cut off for multimode depends of the transmission speed chosen.

Now we need to know the connector type required. There are many choices so it is important to get this right as otherwise you will be stuck with a system that will not be compatible and that will therefore not work for you. Things to note are that most Switches will have an “SFP” port that will support “LC” connectors and most media converters will support “SC” connectors although many are available with an SFP port or multiple SPP ports as well.

Based on all the above the “fibre type” of the fibre optic patch cable can be decided. Available options in the marketplace are multimode OM1 through to the OM5 and then singlemode OS1 fibre optic patch leads to suit those longer distances. If you are looking at installing a completely new system you are well advised not to go with OM1 as this has been effectively replaced with OM3 or OM4 and OM1 is now mainly used for legacy networks only.

 Singlemode fiber has a smaller core size of 9 µm. It typically transmits infrared light from a laser source and delivers more bandwidth and distance than multimode fibre optic cables can. Duplex singlemode fibre optic patch cables are commonly used in long-haul network connections.

The most important thing to be aware of here is that singlemode and multimode fibre optic patch cables are not compatible with each other, unless you use a media converter to convert the signal which can add extra unwanted costs.

Now that we have had a look at all the information we need to assist us when selecting our fibre optic patch cables your checklist when ordering could look something like this:-    

Conclusion:

The fibre optic patch cable market has many products on offer to suit any requirement you might have. If you make quality a priority when choosing your fibre optic patch cables and look for low loss, minimal reflectance and great mechanical strength as a minimum you are well on your way to making the best decision you can. Whilst price is of importance it should not be a driving factor as any downtown your network might have is certainly not going to be cost effective for you in the long run. When your exact requirements are clear to you, choosing the correct fibre optic patch cables should become really easy.

The choice is yours.

  Choose wisely.