09.29.2003 12:00 AM
New World Record for Terrestrial 2.4 GHz IEEE 802.11b Link
Have you tested the range of your IEEE 802.11b wireless link? INTERLINE, a Polish microwave antenna producer has and the results may amaze you. The owner of INTERLINE, Piotr Kroplewski and some of his key employees actively participated in setting up a link that spanned 110 km (about 68 miles). The system used two of INTERLINK's 2.4 GHz 1.1 meter parabolic antennas, with a gain of 27 dBi and a beamwidth of 4 to 6 degrees. RF equipment included an INTEL Pro/Wireless 2011 access point on one end and a Lucent Orinoco "Silver" PCMCIA card. Two 500mw amplifiers were also used in the testing, along with Belden H-1000 and H-155 cables.
The INTERLINK team said the 110 km link was a new world record for a terrestrial 2.4 GHz Direct Sequence Spread Spectrum (DSSS) link using off-the-shelf equipment. The link was set up between an 11-story house in the city of Wroclaw and a glade at 1,400 meters (approximately 4,593 feet) above sea level, near the summit of Sniezka, the highest mountain in Karkonosze.
While it was possible to align the antenna at the city site by visually sighting the mountaintop, on Sniezka, clouds prevented the experimenters from seeing the city. They were, however, able to eventually find the best orientation to the site and the tests began. Only one foreign 2.4 GHz network was discovered during monitoring from the mountaintop site and it had a very low signal level with high noise. The INTEL access point indicated the signal was RSS=8. After adding the 500 mW amplifier, RSS increased to 28. This allowed a negotiated WLAP connection at 1 Mbps. During an FTP file transfer test, throughput was measured at a sustained 40 KB/s, or almost 0.5 Mbps over the 110 km path.
The original story on the testing was available only in Polish. After Slashdot.org
report on the test results, an English language translation of the story behind the record breaking link was put on the web. In spite of the rough translation and multiple translation errors, the story behind the link record link is interesting. See Wi-Fi World Record - 110 km at 2.4 GHz
. This Web site has a map showing the link and photos of the installation at each end of the link, along with a complete list of the equipment and software used in the test.