Today U.S. telecommunications infrastructure has little fiber to the premises, although fiber makes up most long-haul and metropolitan area networks. Realizing the goal of fiber everywhere involves a number of problems requiring research. For example, while the cost of optical components is not a significant problem in core networks because the cost is spread across many users, the components represent a nontrivial expense for local access networks, which serve only one user or a handful of users. How can the cost of optical components be reduced sufficiently to make fiber to the home affordable? What architectural approaches offer the best mix of affordability, performance, and evolvability? What are the future applications that will drive the need for increasing bandwidth?4

Metropolitan area networks are currently receiving much commercial attention. With today’s abundance of fiber in the core, and with access networks creating larger demands, an important focus of research is to develop architectures that effectively handle ever-greater volumes of optical transmission in metropolitan areas. Core networks themselves will require advances, and as more capability is introduced into the access networks, the need will grow to continue to improve the bandwidth-times-distance product, as will demands to increase the performance of national networks.

Wireless networks provide an even more fertile area for exploration. Access to higher bandwidth, which has spurred growing use of the wired Internet and is now becoming available to wireless LAN users (via WiFi and WiMAX) and fully mobile users (via 3G technology), is basic to the creation of the so-called mobile Internet. There are many opportunities for further progress. At the physical level fundamental data rate limits for most environments are still very far from being achieved, and there are practical impediments, such as topography and the costs of certain components such as filters, to enhanced performance. Further development of multiple input, multiple output (MIMO) antenna technology, for example, offers opportunities to drive even greater capacity of wireless networks.
More info: ccent salary