Today, many Latin American governments are convinced of the important role of good communications infrastructure in economic development and are therefore seeking to accelerate new regulatory standards that facilitate growth and respond to the growing demand for basic telephony and cable television (CATV) subscribers. Nine submarine cables installed in the last two years have increased telecommunications capacity by 34% and this gives countries in Latin America the opportunity to develop a sophisticated fiber optic communications infrastructure. It is estimated in conservative terms that by the year 2000 the region will need more than 85 million telephone lines and an investment that exceeds US$100 billion. To adequately meet this demand, both telephony and cable operators will have to play a key role in building network infrastructures as well as in developing basic and value-added services.
The future of CATV networks in Latin America (and other parts of the world) lies in fiber. For example, Telecable Mexicano is updating and improving all its systems with hybrid equipment from fiber/coaxial cables and fiber to the feeder equipment. In Chile, TCI and UIH are installing interactive fiber CATV systems and SONET fiber rings. These operators will soon be able to carry full digital video, as well as analog programming, as 750 MHz amplitude modulated fiber transport technology becomes the new standard.
Important to manage fiber networks
In order to adapt to the new demands of video, voice and data service, modern networks must be very reliable and easy to reconfigure. Many operators are finding that traditional means of network management are already insufficient to handle the new and complex ones demanded by the world of interactivity. In their struggle to maintain participation in their rapidly evolving networks, service providers may be tempted to neglect something as trivial as cable manipulation. This could be costly, as proper distribution of cables and connections is vital to the success of the networks.
The increasing liberalization policies and privatizations that are taking place in the telecommunications industry in Latin America are generating greater competition among service providers. At the same time, consumers' tolerance for periods of service interruption is decreasing, while their demand for better and more reliable services is increasing. For these reasons, it is crucial to organize fiber management in a way that allows quick and easy access to service personnel who need to make changes to network configuration. Equally important is having a monitoring system in place that can report problems before the customer does.
The structure of the fiber
An effective cable management plan starts at the input section with a fiber distribution structure management system. This structure is similar to the central access nerve of all fibers entering from the outside world to the entrance section or central office. It provides a convenient location on the network for fiber optic terminations, splicing, and storage purposes, as well as offering physical access to individual circuits for periodic testing and maintenance purposes.
A flexible structure system like this provides excellent handling of built-in cables.
What to look for in a fiber structure
The two most important characteristics to look for in a good fiber structure system are modularity and flexibility. A modular fiber structure design allows the network to grow from a single fiber to thousands of fibers without sacrificing space or functions. Flexibility allows the structure to serve the current fiber network while being able to meet future demands. In addition to modularity and flexibility, there are many other options to consider when selecting a fiber structure system. Points such as design configuration, larger or smaller capacity options, splices in or out of the structure, and built-in cable management should be evaluated.
A well-designed and truly flexible fiber structure must have the ability to accommodate any existing equipment or networking applications. Well-designed built-in cable management equipment will maintain a correct fiber bending radius of a minimum of 1.5 inches (3.8 cm) across the entire length of the structure, thus eliminating cable breakdown or power loss due to bending.
If routing boxes are included in the fiber path, the fiber follows a path and is physically protected from accidental blows from maintenance personnel or other equipment. A well-designed fiber structure should also have intermediate bay areas with enough space to store surplus fibers and angular retainers at 45 degrees with adapters that protect the fiber from sudden folds, and thus prevent ruptures or undue pressures on the fiber.
Another aspect that should be taken into account when looking for a good fiber distribution structure is whether it can easily incorporate additional optical functions. Value-added modules include elements such as disconnector/combiner modules, video splitters, wavelength splitter multiplexers, and optical switching module.
System security is also a concern of many network administrators, particularly when the computer is located in easily accessible or vandalism-prone areas. For this reason, the design of a good distribution structure should include panels or boxes that can be locked to restrict access to them. Some fiber distribution structures offer a box with a transparent front cover, which allows basic maintenance checks without having to open the lids of the boxes.
Just as there are multiple types of fiber structures and a host of adaptable fiber options, there are also many different connector options, including SC, FC, or ST. A variety of panel options are also available. High-density panels are typically available in 19- or 23-inch versions, with 48, 72, or 96 terminations. What is the most appropriate size for each specific network? How important are angular retainers? What are the acceptable levels of insertion loss? And how should connected cable assemblies be treated? These are some of the many questions that service providers must ask themselves when planning their networks. Almost all of them will need help making the decisions that best fit the particular needs of their networks. It goes without saying how important it is to find a good provider that understands the requirements of the network and can provide solutions with appropriate end-to-end equipment. It will depend on whether a flexible and well-planned network is built.
