Free Space Optics Communication

Abstract

Today’s information economy depends on the transmission of data, voice and multimedia across telecommunication networks. Despite new technologies that enable legacy copper telephone lines to carry information more efficiently, optical networks remain the most ideal medium for high-bandwidth communications. There are two distinct types of optical communications: fiber optics (fiber-optic cable) and optical wireless based on free-space optics (FSO) technology. For long-haul network deployments, nothing is better than fiber. When coupled with new dense wavelength division multiplex (DWDM) technologies, fiber optics is capable of carrying information at 40 Gbps (gigabits per second). However, for making connections over relatively short distances in cities—the “last mile” between the fiber and the metro concentration of end-users—fiber and optical wireless often rely on one another for success. The two technologies not only come from the same family tree, they are nearly identical twins. The last two decades have seen huge investments in building a global fiber network core, leveraged with the promise of generating increased bandwidth access and services to meet growing needs. Meeting projected bandwidth needs, however, depends on customers having access to optical networks. This has yet to fully occur in the metropolitan areas, which remain a relatively untapped bandwidth access market where a mere 7 percent of end-users are connected to fiber optic networks. Fiber optics is being deployed at a measured and sustained pace, but the cost to do so is often high, the process long and the investment irreversible. Conversely, optical wireless complements fiber optics in metro networks and local area networks (LANs) with considerably less expense and faster deployment. At one point, many telecommunications industry leaders and technology observers dreamed of an all-fiber metropolitan network, but this vision is impractical for several reasons. The process of laying fiber in metropolitan areas is time consuming and prohibitively expensive. Ongoing preservation and restoration of fiber-optic systems in the event of accidental disruptions or natural disasters is also time-consuming and technically challenging, as service providers must address the concerns of bandwidth dependent customers frustrated with every hour of lost network access. That said, all-optical fiber optic networks, with their high-bandwidth capacities, are promising. a world complete with fiber connections for all is decades from reality. a combination of broadband access technologies provides the most cost efficient and reliable solutions for addressing both primary connections and backhaul.