11-12-2004, 20:58 #6
eu uso 5.8 (proxim tsunami MP11a) pra levar o sinal ateh as repeticoes... eh um show. Mas na chuva nao se comporta muito bem. E tem esse problema dos radares ae. Estava lendo umas materias a respeito desses radares... os caras usam amplificadores monstros. Se passar uma aeronave usando isto seu sinal vai pra PQP...
eh aquela historia se ficar o bicho pega... se correr o bicho come... tem que arriscar.
Fora isso tem todos os mandos e desmandos das telecom...
12-12-2004, 12:57 #7Jesael
Essa é boa. A idéia de liberar banda dos canais analógicos de TV para Wi-fi é interessante. Só que nesse texto fala-se do contrário: o medo militar de ser interferido por wi-fi. Muito embora o sinal do radar seja potente, o eco do alvo é um sinal pequeno. Já pensou uma torre sendo confundida com um alvo?
Acho melhor os provedores estreitarem os laços com a AlQaeda. Osama pode ajudar.
update Tech companies and the Department of Defense have reached a compromise on the future of wireless networking, addressing military concerns about radar interference.
The two sides said Friday that they had reached a resolution that establishes a new radio frequency threshold for products using unlicensed radio spectrum--primarily Wi-Fi products. Wi-Fi is a technology that lets devices located within a 300-foot radius communicate with one another wirelessly.
The Department of Defense was worried that the cumulative effect of Wi-Fi products could interfere with the military's use of radar because the regions of the spectrum in which Wi-Fi and radar operate overlap somewhat.
"We feel comfortable that the new limits will protect military radar," said Badri Younes, a director of spectrum management at the Department of Defense.
The two sides had been working on creating limits that allowed devices to continue to use Wi-Fi technology, domestically and internationally, while not interfering with radar.
"No one is entirely happy, and that's the essence of compromise," Intel spokesman Peter Pitsch said.
Official statements about the resolution are expected next week from various government agencies, such as the National Telecom Information Agency (NTIA).
The resolution will also apply to the additional spectrum that is being requested by Sens. Barbara Boxer, D-Calif., and George Allen, R-Va., under the proposed Jumpstart Broadband Act. The bill proposes opening up an additional 255MHz of contiguous spectrum in the 5GHz band. A 300MHz slice of the 5GHz band is being used for wireless networking, while only 83MHz of spectrum is being used in the 2.4GHz band.
"Now that this technical issue has been resolved, Congress should proceed to enact the Boxer-Allen bill," Boxer said in a statement released late Friday. "This bill is vital for the buildout of broadband, a technology that has shown that its use has a direct, positive impact on productivity and learning."
The two senators had been promoting the legislation as a means of bringing broadband access to the masses. The potential revenue number of broadband subscribers in rural areas and small cities does not outweigh the cost of introducing the service in those areas. The act would lay the groundwork for more powerful, cheaper long-range wireless networks for providing broadband access. The bill also sets "rules of the road" for the launch of wireless networks to avoid transmissions interfering with bandwidth used by others such as the military.
The new resolution removes an obstacle to the acceptance of the bill and encourages the use of the 5GHz band in the United States and internationally. The use of this band is likely to be a significant topic at the upcoming World Radio Conference in June in Geneva.
The ailing communications industry has been looking for a silver lining in the slumping tech sector, and many companies have latched onto Wi-Fi in hopes of rejuvenating consumer interest. The technology is making its way into everything from PCs to DVD players. Industry analysts are forecasting significant growth for wireless gear in the coming years as consumers complement their high-speed broadband access with wireless networks and as manufacturers add Wi-Fi to devices such as tablet PCs and handhelds.
Government agencies other than the military have been working to promote the use of wireless networking. Earlier this month, the Federal Communications Commission floated the idea of opening up unlicensed parts of the broadcast television spectrum for use by Wi-Fi devices. The move would help the FCC push TV broadcasters toward digital television, which it is doing in order to free up the analog TV spectrum for uses such as wireless home networking technology.
14-02-2006, 17:22 #8felipaoPostado originalmente por Bronius