Fiber in the Loop

Fiber in the loop, often referred to as FITL, is a system to implement and deploy fiber optic transmission in access networks such as that of PSTN. Fiber in the loop technology uses pair of cables that run from a central office to a customer location. The customer location can be a telecommunication cabinet (Fiber To The Cabinet – FTTC), home (Fiber To The Home – FTTH), node (Fiber To The Node – FTTN) or premise (Fiber To The Premise – FTTP). In effect, FITL can be used with any FTTx architecture.

Let us now discuss the basic components of an FITL system:

• Optical Line Transmission (OLT)
  • OLT is used to terminate the optical fiber cable at service provider’s end
• Optical Network Unit (ONU)
  • ONU is used to terminate the optical fiber cable at user’s end
• Optical Distribution Network (ODN)
  • ODN is used to split the main fiber among the end users, creating a point to multipoint architecture

FITL has several advantages over the traditional cabling systems and techniques. Some of the advantages of FITL are highlighted in the following section.

• FITL requires very less maintenance as compared to traditional cabling systems
• FITL is immune to electro-magnetic interferences and other environmental factors
• FITL is scalable, a single cable can serve a large number of end points
• FITL is easier to manage and requires very little space for deployment

The above mentioned advantages of FITL system make them a very favorable choice for deployment in next generation networks where fiber is available at every doorstep. FITL networks provide very reliable and high bandwidth connections to the internet and other infotainment services such as digital television, telephony, home automation and security systems.

Apart from the above mentioned advantages of FITL, there are some limitations that should be taken care of before deploying a robust FITL system. Firstly, FITL systems require power from a reliable source as the whole network is dependent on a sustainable power source for its smooth functioning. Secondly, a massive capital investment is required for implementing the FITL system. This capital investment must have a justification in case of lesser number of consumers and low return on investment cases.

All in all, FITL is another revolutionary technology which is here to stay. Research and development efforts are being carried out on a large scale to make this technology more reliable and cost-effective.