Building Residential Fiber Networks Faster at a Lower Cost

The broadband FTTH market is in its infancy in North America and very little attention has been paid to the last 150’ drop necessary to bring a low fiber count connection into customers’ homes. Currently a broadband operator’s fast ROI lies in business and multi-dwelling unit (MDU) applications. To date, the ROI model for single family units (SFU) doesn’t measure up.

Often an operator’s fiber installation expertise is limited, so they rely on subcontractors who have the equipment, know-how, and business model necessary for long fiber runs. But, whether operator or subcontractor, those who have attempted a last fiber drop using the same techniques that work for trunk fiber installations have found themselves faced with time consuming, unprofitable deployments.

If the future of connectivity lies in SFU residential fiber networks, as many in the industry suggest, then a long-term goal probably needs to be an installation solution that is different from the one employed for trunk fiber networks. With low SFU fiber counts there are lower cost options for both capital equipment and operational efficiencies to be realized.

Different Products/Different Methods/Different Personnel for Residential Fiber Networks

Speaking generally, long fiber trunk runs carry large bundles of fiber for long stretches.  These bundles transmit vast amounts of data, video, etc. to large segments of the network so reliability and durability are crucial.  At the ends of these bundles it is necessary to connect each fiber to another fiber. 

Doing this on a large scale, while maintaining signal integrity, often requires a “mass production” model for making connections; the more repetitive and consistent you can be, the faster you can do them, thus saving time and money. 

The investment in equipment, training, and personnel to achieve this assembly line style can be large, and that is why many operators outsource it to a contractor.  In order to ‘process’ the large number of fiber connections necessary, most subcontractors that specialize in fiber optics will use an expensive fusion splicer that requires training to use and time to set up.

In comparison, making the last drop in the network is a completely different animal.  When connecting fiber to the home, you are only working with one or two fibers at a time.  The setup time and the installation time for each home cannot be done in bulk.  You need individual setup time to make the connection for each home.  Because many subcontractors have an investment in their equipment, training and personnel, they will be inclined to use the same methods for this drop that they have used in the trunk fibers.  The result is a very expensive installation for a single home.

The FTTH Installation Problem in Dollars and Cents

Approximately 80% of cost in an FTTH deployment goes to labor.  By having a distinct installation method for the last drop, you can achieve a time savings of as much as 1 hour per home, compared to using trunk installation methods.

In the trunk, setup, preparation and splicing time for a 144 fiber cable averages out to about 4-5 minutes for each fiber, or 10-12 hours for the whole cable. The setup time is done once, and the splicing is done repetitively. If you do fusion splicing in the residential drop, you have to do the same setup that you do in the trunk for each drop location even though the splicing is limited to 2-4 fibers.  Therefore, total connection time for a two fiber drop cable, including set up, cleaving, fusing, and storing slack takes 30 minutes per location or one hour for two fibers.

If turning up subscribers quickly and efficiently is important, then other solutions, such as using pre-terminated, pushable fiber, would reduce labor time and personnel required – in fact, would allow you to use your technicians’ existing skills.

The Residential Fiber Network Drop is a Different Animal

Because of the difference in scale and installation requirements, reducing the cable preparation and connection time is crucial to keeping costs down.  You cannot “mass produce” splices in the drops so you need an efficient method of making these connections. 

You would be better served using different products, different methods, and different personnel for the drop in an FTTH deployment.  If you can scale with existing resources, large upfront investment can be avoided in favor of other projects with greater return potential.

Using Pushable Fiber

Using field-fit connectors, or pre-terminated connectors, and pushable fiber means that you eliminate much of the setup time and connection time for the drop.  Many pre terminated solutions are small enough to be pushed through microduct and then can be field assembled with an industry-standard connector in less than 3-4 seconds.

Operators can use their current “drop technicians” to do these installations without having to invest significantly in capital or outsourced skill sets.  There is less capital required for splicing equipment. Pre-terminated cables provide a reduction in installation time of over 60-80% - when compared to traditional installation methods.  

Pushable fiber is also highly scalable in terms of uptake or subscription rates, costing little labor and equipment to deploy fiber whether it’s to a single home, or multiple homes in a single pass. With less equipment and skillsets required, pushing fiber to the home takes a fraction of the time and money of more static traditional methods, such as blowing, burying, hanging or fixing fiber cables.

Signal Loss - Fusion Splice vs. Mechanical and Pre-Terminated Connectors

Some will make the argument that a fusion splice is a more reliable and better performing connection than a mechanical connector or a pre-terminated connector.  The typical loss budgeted for a fusion splice is 0.1dB, while it is 0.3dB for a mechanical connector and 0dB for factory pre-terminated connectors.  Considering that most subscriber drops will have two localized optical connections between their devices and the network hub, using connections that install fast and with ease should be considered. It is highly unlikely that the optical loss budget in the network design will be affected by these last two connectors - because the loss in each drop is not aggregated in the distribution network, there will be negligible impact on the loss budget.

You may wonder why we are making a big deal about the drop to the home.  We believe in learning lessons from the trials of others – and it is clear that recent U.S. FTTH attempts have not all gone that extra mile in planning to be sure that a whole project doesn’t lose money. In most of the cases complications arose because operators/installers approached it as though the fiber plant was one homogenous network from headend to Customer Premise Equipment. 

When you compare all the factors we have described above for trunk vs. drop applications: unique products, different techniques, different personnel, different training, and capital investment structures; you can easily see that the residential drop portion of the network is emerging as a distinct new area of focus for the communications delivery realm.  Paying special attention to this segment will reward you in time and money saved.