DARK FIBRE SOLUTIONS: CHALLENGES AND LIMITATIONS
“Dark Fiber” or sometimes spelled as “Unlit Fiber” is defined as being an unused optical Fiber cable or networks, which are usually used in
In addition to the "traditional" optical fiber networks above, there is recent interest in deploying a new category of optical networks. This is because, for their construction and for their effective deployment and end-use, the parties involved generate and promote new business models that are completely different from those that already exist. Such models are currently deployed in many parts of North America (Arnaud, 2002). With regard to European countries, apart from a successful pilot attempt in Sweden (STOKAB AB, 2004), such an initiative is still "immature". However, because of the challenges of broadband and competition, these networks can be valuable alternatives for the wider development of potential applications of the information society, particularly in the context of recent joint initiatives of the European Union. EU (Chochliouros & Spiliopoulou-Chochliourou, 2003a, European Commission, 2002).
What is dark fiber?
"Dark fiber" is typically an optical fiber dedicated to a single customer, where the customer is responsible for attaching telecommunication equipment and lasers to "light up" the fiber (Foxley, 2002). In other words, a "black fiber" is an optical fiber without communication equipment; that is, the network owner gives both ends of the connection in the form of fiber connections to the operator without intermediate equipment. In general, dark fiber can be more reliable than traditional telecommunications services, especially if the customer deploys a diverse or redundant fiber-to-black route. This option, under certain circumstances, may encourage more exploitation and / or deployment of the market while increasing competition (Chochliouros & Spiliopoulou-Chochliourou, 2003c). Traditionally, fiber optic networks have been built by network operators (or "carriers") who take responsibility for lighting the appropriate fiber and providing a managed service to the customer.
Black fiber can be explicitly estimated as a very simple form of technology and is often referred to as "technologically neutral". Black fiber sections can be very easily merged so that a continuous wire exists between the customer and the final destination. As such, the great advantage of the dark fiber is that no active device is required in the path of the fiber. Due to the non-existence of such devices, a black fiber in many cases can be much more reliable than a traditional managed service. Services in this latter category typically involve a significant number of particular devices in the network path (eg, ATM switches, asynchronous transfer mode, routers, multiplexers, etc.); each of these intermediaries is likely to fail and this becomes the reason why traditional network operators must deploy complex infrastructure and other systems to ensure compatibility and reliability. For greater efficiency, many customers generally choose to install two separate dark fiber links to two separate service providers; However, even with an extra fiber, dark fiber networks are cheaper than services managed by a network operator.
With customer-owned dark fiber networks, the end customer becomes an "active entity" that ultimately owns and controls the relevant network infrastructure (Arnaud, Wu and Kalali, 2003); that is, customers decide which service provider they want to connect to for different services such as telephony, cable TV and the Internet (New Paradigm Resources Group, Inc., 2002) . In fact, for the moment, most existing client-owned dark fiber deployments are used for the provision of Internet-based services and / or applications (Crandall and Jackson, 2001). The black fiber industry is still evolving.
With the black fiber option, customers can have other choices in terms of reliability and redundancy. In other words, they may have a single unprotected fiber link and be as reliable as their current connection (Arnaud et al., 2003, New Paradigm Resources Group, Inc., 2002); they can use an alternative technology, such as a wireless link for backup in case of fiber breakage; or they can install a second geographically diversified black fiber link whose total cost is always cheaper than a managed service as described above. In addition, because the fiber has a higher tensile strength than copper (or even steel), it is less susceptible to wind and snow breaks.