Service providers, consultants, engineering companies and contractors are all working together in building Fiber to the Home (FTTH) networks. The methods that they’re using to build and design these networks in most cases are based around a set of traditional standards.
The largest issue when using traditional methods to build a FTTH network is that they’re very labor intensive especially in the area of splicing. In most cases, 70 percent of the capital spent is for labor. Because of this, manufacturers are being pushed to develop a more cost effective way to build these networks.
Plug and Play the FTTH Way
So what is the next evolution in FTTH? The answer is, actually a decade old innovation whose time has come of age. That is: plug and play network elements. With this option, connectorization replaces splicing so the need for skilled labor is reduced and the cost to deploy a FTTH network goes down. When companies build a FTTH network, they have a tendency to look at labor and material costs independently. Price is where modular products still struggle when compared to more traditional network elements. However, if the total cost of labor and materials is examined together, the discovery of the modular design will win out. In addition, any time fiber terminations can be mass produced indoors in a controlled environment, the cost will go down and reliability of connectors will increase.
The consumer/end-user has adopted this approach for the convenience. For example, when you go out and buy a RJ45 patch cord to provide connectivity from your modem or network interface device to your computer, the consumer “last mile,” you don’t buy it terminated on one end and not on the other. Why does service provider do it this way?
Currently, MTP/MPO connectors are available in 4-, 8-, & 12-fiber configurations. The connector gained popularity first in enterprise networks, where data was on the only content being delivered and where distance between network elements was relatively short, and the loss could be overcome. The connector for the service provider network was not nearly as popular due to the limitations in performance.
Previous versions of the MTP/MPO displayed insertion and return loss performance that was unacceptable for the tight link loss requirements for the service provider networks being built. Two to 5db of loss were not uncommon, which, if used, required , more expensive equipment to account for that kind of loss. What’s more, it was expensive to produce a multiple count fiber connector due to the precision involved in the manufacturing process. As a result, manufacturers would have to sell a large amount of the product to recoup cost before making a return on investment.
Another obstacle in producing a low count multi-fiber connector has been the division between manufacturers. Cable, fiber termination and network equipment manufacturers need to share technologies and work together to develop a group of products that will mesh. For example, no service provider is likely to jump into an expensive connector that is inconsistent in performance across all channels – especially at a level that requires more expensive gear to overcome with standardization across manufacturers.
The Only Constant is Change
A lot of things have changed. The MTP/MPO is built to a standard now. Of note is the variable male/female (with or without pins) and keyed connectors. This can still be confusing.
But performance has dramatically improved. A premium connector now will yield guaranteed .3dB of loss across all channels. For a 12-fiber connector, this is impressive.
Improvements in manufacturing processes and techniques are producing capable, repeatable, and higher first pass yields resulting in more and acceptance in the industry. This, in turn, is driving the price down to more attractive levels.
More Fiber Connectivity Needed
Before FTTH, outside plant engineers used fiber mostly for the transport of large amounts of data between offices. Fiber cables were terminated on a patch panel in an office where circuits were patched through via single or dual fiber patch cords. Hence, the single fiber connector was and still is the most widely used. With the advent of FTTH, there’s a need for connectors with counts between one and 12 in order to fill the engineering requirement. Typically, an engineer will design a FTTH network where terminals will feed four to six homes. This is a carryover from the days of designing copper networks.
The reason this design is carried over is to allow ease of service hook-up for the installation technician. (Hence the industry term “time of dispatch.”) In the FTTH world, decreasing the time of dispatch has been a challenge for all carriers. Typically, four to eight hours are required for a service installation — so any time that can be shaved off of the install translates into cost savings and a better customer experience. A modular network will also help reduce the labor involved with the installation as well as splicing.
MPO is Back
The new and improved MTP/MPO designed for service provider networks are now making their way into the product development efforts of active and passive gear manufacturers. They are now looking at incorporating this technology into fiber terminating equipment as a plug and play solution.
The MPO is also an attractive solution because it’s similar to “Stick and Click” (SC ) in the fact that it’s an industry standard. The MPO has the ability to accommodate one to 12 fibers in its footprint, so it’s an attractive option for plug and play products. The only thing holding up the usage of the MPO is cost. Since it hasn’t been widely developed in the industry as a product line, it’s still not seen as a cost effective option.
In Conclusion: Collaboration
In conclusion, as the deployment of fiber grows in FTTH, data center, smart grid and wind farm technologies, the demand for skilled splicing technicians will grow. This will be a major problem because the limited pool of technicians that currently exists can’t keep up with the demand and the learning curve for future techs will be too great. So, the need to develop a simple, cost effective low count fiber connector that can be incorporated into a full gamut of products is in the immediate future. The MTP/MPO is clearly leading the race to this end.
About the Author
Brian Schrand, Clearfield’s Senior Member of Technical Staff, with more than two decades in the telecommunications industry, is a highly regarded fiber network expert and resource. Before joining Clearfield in 2010, he was Senior Specialist for Network Engineering, Construction and Operations at Cincinnati Bell Telephone (CBT), the 9th largest telephone company in the U.S.