Fiber Optic Cable Assemblies

Field Terminated VS. Pre-terminated Fiber Optic Cable

With more and more fibers, connectors and deployment strategies available in data centers, IT managers have become increasingly concerned with choosing the best termination method for their environment to ensure performance, rapid deployment, manageability, and reduced total cost of ownership, as well as scalability for future growth. Although manufacturers have come up with dozens of connector styles and ways to install them, there are really only two major termination solutions: field terminated and pre-terminated. When choosing fiber optic cable, besides considering fiber type, connector type or jacket type, we also have to consider whether the cable needs to be field terminated or pre-terminated. This post will introduce fiber optic cable with these two different termination methods and tell which one is better for your applications.

Field Terminated Fiber Optic Cable

Field terminated fiber optic cable, as its name suggests, is the optical fiber cable applying field termination method or terminated after installation. Field termination method is the original fiber optic connectorization method, which used to be popular on the majority of fiber optic cables years ago. When optical fiber is terminated in the field, the cable must be pulled between points and attached to patch panels at both ends of each run. Before it can be attached to the panel, technicians must attach connectors to each strand. Here shows the tools needed in field termination.

preparion for field termination method

Advantages of Field Terminated Fiber Optic Cable
  • Exact Length and Slack Storage Not Required: Because backbone cable is cut to length before adding connectors, it is not necessary to predetermined lengths, which can cut down on lead times. This also eliminates the need to implement slack storage.
  • Easy Cable Pulling: When using field terminated fiber optic cable, bulk cable can be easily pulled from either end of the circuit.
  • Maximum Flexibility in Meeting System Requirements: This is actually the biggest advantages when using field terminated fiber optic cable. You can just pull the fiber cables and terminate them later, so that you can do on-the-spot repairs wherever there’s a defective fiber link.
Disadvantages of Field Terminated Fiber Optic Cable
  • Highest Labor Cost and Slowest Installation: Fiber optic cable with field termination method is high cost. There are many steps and tools needed to properly terminate the fibers. In addition to having the appropriate “bag of goods” to perform this procedure, it is also necessary for the technician to have proper training and skills. Besides, it takes longer to install field connectors, requiring additional time for installation.
  • Termination Quality Issues: The yield of acceptable connections is directly related to the skill level and experience of the technician, and reliability is jeopardized as field terminated connectors can fail or perform below acceptable signal loss tolerances. This will result in the cost of redoing work that has failed, as well as the cost of additional connectors. Field terminated fiber optic cable may be inexpensive at time of purchase, but extraneous expenses encountered in the field can rapidly increase.
Pre-terminated Fiber Optic Cable

Fiber optic cable with pre-terminated method goes through the same procedure as field terminated fiber optic cable, but these steps are taken at the manufacturer’s facility or cable assembly house as shown below and delivered to the job site with the connectors already terminated, properly polished, and the entire cable assembly tested on either both or one end. Pre-terminated fiber optic cable has been a norm in telecommunication networks, since it provide more convenience, easier installation and higher performance than field terminated fiber optic cable. Fiber optic patch cable is the most commonly used pre-terminated fiber optic cabling in data center and for high-performance and high-density application, we turn to MPO or MTP cable assemblies.

factory-preterminated

Advantages of Pre-terminated Fiber Optic Cable
  • Superior Performance: One of the main advantages for specifying pre-terminated fiber optic cable is that the controlled factory processes with pre-terminated results in superior performance. Consistent, high quality connector end face geometry results in lower insertion loss and better end-to-end attenuation in the system.
  • Time & Cost Saving: Because cables arrive ready for immediate installation, there is no cable termination preparation, no connector scrap, no cumbersome tool kits or testers needed and no specialized testers. Customers have reported that pre-terminated fiber optic cables cut the costs at an average of 20% to 30%, mainly due to time and labor saving over field terminated practices.
Disadvantages of Pre-terminated Fiber Optic Cable

The biggest disadvantage of pre-terminated fiber optic cable is that the prepolished connectorized fibers can cost much more than epoxy-style field-polish connectors. And the cable length needs to be precisely measured. If pre-terminated cable is too short, you need to install a replacement; if it is too long, you have to deal with the installation issues associated with managing the extra cable length, which will also case additional expense.

Which One Should We Choose?

Actually, most people would like to choose pre-terminated fiber optic cable, since it can provide a easier way to install, but there still exist some people prefer to using field terminated cable. When trying to figure out which type of fiber optic termination solution is best suitable for your installation, factor in all costs including consumables, tools, labor, proper training should be considered, and if needed, re-work. Also keep in mind the time that you are allowed to terminate and install the fiber at the job-site.

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