mance—and wide enough penetration of services reaching that performance level—to encourage the development of new applications. These definitions reflect the central “chicken-and-egg” conundrum: an application will not be made available unless a sufficient number of subscribers have broadband connections with performance high enough to support the application, yet service providers will not invest in higher-performance broadband until they know that there will be sufficient demand for the service. Residential broadband capabilities today, with speeds typically ranging from several hundred kilobits per second to several megabits per second downstream and several hundreds of kilobits per second upstream, support familiar applications such as Web browsing, e-mail, messaging, interactive games, and audio download and streaming. The next performance plateau, which is not widely available at present, provides downstream speeds of several tens of megabits per second, thus enabling new applications such as high-quality streaming video or rapid download of full-length audiovisual files. With the addition of comparable upstream speeds, computer-mediated multimedia communications —to enable more effective telecommuting and distance education, for example—become possible. Fiber-to-the-home (FTTH) would offer the highest performance—gigabit speeds both up- and downstream. Investment in FTTH has lagged other options because of costs and uncertainty about demand for its capabilities. Some investment currently is providing opportunities for experimenting with technology alternatives and applications and for learning about demand. At the same time, a variety of wireless options provide either cost-effective alternatives (especially for remote locations) to wireline or mobility and ubiquity that complement wireline technologies.

Development, deployment, and adoption will be an ongoing process that works through several mechanisms: incremental upgrades and reallocation of capacity in existing broadband infrastructure, improved end equipment that permits faster performance over the existing infrastructure, and installation of new infrastructure. These improvements may or may not require new technology, but all require investment premised on market demand and willingness to pay. Indeed, many factors—not simply technology—will shape the pace and distribution of broadband deployment.

While broadband is sometimes characterized in terms of a horse race between DSL and cable and between the incumbents that use these technologies, the committee believes that the long term will be technologically diverse, reflecting geographical and market variation, the maturity of and experience with different technologies, topography, and the condition of existing infrastructure. Because local conditions vary, broadband’s availability will be quite uneven, especially in the earlier stages. The nature



The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement