tailieunhanh - The next great telecom revolution phần 5

Chuỗi của nó có thực sự thanh silicon, 150 200 nm trong mặt cắt ngang và khác nhau, từ 6 đến 12 mm chiều dài (micromet là một phần triệu của một mét; nanomet là một phần tỷ của mét, chiều dài của ba nguyên tử silicon trong một hàng). | FASTER NETWORKS 81 Next-Generation Telecom Network Several scientists working in collaboration are laying the groundwork for a new wireless and optical fiber-based telecommunications network that aims to bring reliable high-speed Internet access to every home and small business in the United States within the next few years. Funded by a five-year million National Science Foundation grant the 100 Megabits to 100 Million Homes research project brings together scientists from Carnegie Mellon University Fraser Research Rice University the University of California at Berkeley Stanford University Internet2 the Pittsburgh Supercomputing Center and AT T Research. The coalition believes that the growing demand for communications combined with newly emerging technologies has created a once-a-century opportunity to upgrade the nation s network infrastructure. What the copper-wired telephone network was to the 20th century the fiber network will be to the 21st says Hui Zhang the project s principal investigator and a Carnegie Mellon associate professor of computer science. Today we have 500 kilobits reaching 10 million American homes he notes. Zhang is looking toward creating a system 100 times faster and that reaches 10 times more households. We must make the system more manageable more secure more economical and more scalable and we must create an infrastructure that can support applications not yet envisioned he says. The creation of a network to serve 100 million households with two-way symmetric data communications service at 100 megabits per second is a tremendous challenge that reaches far beyond technological issues. Universal availability of such a network promises to bring fundamental changes to daily life and could substantially raise its users standard of living. Barriers to the network s creation however extend beyond straightforward deployment and cost issue fundamental innovations in the way networks are organized and managed are also an issue. .