Intel has found a way to send WiFi signals over a distance of more than 60 miles:
Intel has announced plans to sell a specialized Wi-Fi platform later this year that can send data from a city to outlying rural areas tens of miles away, connecting sparsely populated villages to the Internet. The wireless technology, called the rural connectivity platform (RCP), will be helpful to computer-equipped students in poor countries, says Jeff Galinovsky, a senior platform manager at Intel. And the data rates are high enough--up to about 6.5 megabits per second--that the connection could be used for video conferencing and telemedicine, he says.
The RCP, which essentially consists of a processor, radios, specialized software, and an antenna, is an appealing way to connect remote areas that otherwise would go without the Internet, says Galinovsky. Wireless satellite connections are expensive, he points out. And it's impractical to wire up some villages in Asian and African countries. "You can't lay cable," he says. "It's difficult, expensive, and someone is going to pull it up out of the ground to sell it."
Already, Intel has installed and tested the hardware in India, Panama, Vietnam, and South Africa. Later this year, the company will sell the device in India, with a target price below $500. The point-to-point technology will require two nodes, which could provide "full back-end infrastructure" for less than $1,000, Galinovsky says.
One node is usually installed at the edge of an urban area, wired to a local-area network cable, he explains. Using a directional antenna, the device shoots data to a receiving antenna as far as 60 miles away. Any farther away, and the system encounters problems due to the curvature of the earth. Practically, most links will be set up less than 30 miles away from one another. Once a node is installed in a village, the connection can be dispersed using standard cables and wireless routers, Galinovsky says.
There is nothing particularly innovative in the antenna technology and the router hardware, he says. The trick, he explains, comes in the software that the radios use to communicate with each other. "If you take standard Wi-Fi and focus it," Galinovsky says, "you can't get past a few kilometers." The reason is that one radio will send out data and wait for an acknowledgment from the other radio that the data was received. If the transmitting radio doesn't receive the acknowledgment in a certain amount of time, it will assume that the data was lost, and it will resend it.