Friday, June 22, 2007

WiFi With A 238 Mile Record Reach

Researcher Ermanno Pietrosemoli has set what appears to be a new record for the longest communication link with Wi-Fi. Image Credit: Escuela Latinoamerica de Redes

WiFi With A 238 Mile Record Reach

So you are sitting in your home in Los Angeles and you notice that among the available WiFi networks in your area, you have your own at&t DSL connection, a neighbors cable based wireless signal, and one from Hearst Castle on the central coast of California.

Well, that is about the same distance as someone in Venezuela was able to achieve on a WiFi network portal … that is, to set up a WiFi connection with the reach of about 238 miles using mostly “off-the-shelf” equipment and a few hacked parts.

Imagine the additional coverage one could achieve on a DSL in areas where the phone company has neither hardwire service or cell towers (at least until a direct satellite link is affordable). Judging from what networking guru Ermanno Pietrosemoli was able to prove when he established a wireless connection between a PC in El Aguila, Venezuela, and one in Platillon Mountain, this may be both a financially and technologically feasible solution for some remote communications applications.

Excerpts from CNET News Blog –

New Wi-Fi distance record: 382 kilometers
Posted by Michael Kanellos - CNET News Blog - June 18, 2007 9:18 AM PDT

Researcher Ermanno Pietrosemoli has set what appears to be a new record for the longest communication link with Wi-Fi.

Pietrosemoli, president of the Escuela Latinoamerica de Redes (which means networking school of Latin America) established a Wi-Fi link between two computers located in El Aguila and Platillon Mountain, Venezuela. That's a distance of 382 kilometers, or 238 miles. He used technology from Intel, which is concocting its own long-range Wi-Fi equipment, and some off-the-shelf parts. Pietrosemoli gets about 3 megabits per second in each direction on his long-range connections.

Most Wi-Fi signals only go only a few meters before petering out. Conventional Wi-Fi transmitters, however, send signals in all directions. By directing the signal to a specific point, range can be increased.

Image Credit: Escuela Latinoamerica de Redes

Honing the signal, however, means that the receiver and transmitter have to be aligned. Trees, buildings and other objects that get between them can sever the link. The curvature of Earth, misalignment between the transmitter and receiver, as well as shaking and any sort of movement at the transmitting or receiving end can also impair the signal. (To ameliorate some of these factors, Intel has created a way to electrically steer the signal, which in turn increases bandwidth.)

Geography was on Pietrosemoli's side. El Aguila and Platillon Mountain sit in the Andes, which form fairly jagged peaks in this part of the range.

The old record was 310 kilometers. Swedish scientists made a link between a balloon and an Earth-bound station.
Platillon Mountain, Venezuela directional INTEL antenna aimed at a location 238 miles away. Image Credit: Escuela Latinoamerica de Redes

Intel, along with organizations like Inveneo, are testing the feasibility of long-range Wi-Fi as a communication link in Uganda and other emerging nations. Long-range Wi-Fi isn't as robust at WiMax, but the towers cost a lot less. Some hobbyists have accomplished a long-range Wi-Fi connection with low bandwidth.

Similar experiments are being carried out in the United States as well. A long-range Wi-Fi link connects Intel Research's Berkeley Lab and a Sun Microsystems lab on the San Francisco Peninsula, more than 20 miles away.
Reference Here>>

1 comment:

manochandra said...

Superb hope this will give us low cost , relaiable secure communication