账号:
密码:
CTIMES / 社群討論 / 新聞報導論壇
讨论新闻主题﹕委科学家成功以Wi-Fi链接相距382公里的计算机
根据外电消息转述委内瑞拉《国民报》的报导消息指出,委内瑞拉科学家近日刷新了Wi-Fi无线网络技术应用距离的世界纪录,两台距离382公里的计算机,可用Wi-Fi技术相互连接起来。 外电报导中表示,委内瑞拉安第斯大学拉美网络学院教授Ermanno Pietrosemoli领导一组20人的工作团队,成功地把分别被放置在委西南部梅里达州和中部瓜理科州两座山峰上的计算机,用Wi-Fi无线技术连接起来...

Hong Yi
(不在在线)
nbsp;
来自: 台北市
文章: 64

发 表 于: 2007.08.15 10:52:47 AM
文章主题: 委科學家成功以Wi-Fi連結相距382公里的電腦

這樣的距離夠長了,不過也顯示委國很空曠,人煙稀少。連青少棒代表隊都不給簽證了,難怪空曠無人煙。

WiFi當然可以透過天線技術來強化傳輸距離,不過對行動中、甚至是在快速移動中的交通工具內就不是目前的架構可以勝任的,也許將來可以再發展成行動通訊標準,不過開發中國家的目標還是以經濟可用為優先。

检视会员个人资料个人资料 回复文章 回顶端

Clif
(不在在线)
nbsp;
来自: 台灣
文章: 42

发 表 于: 2007.08.15 11:07:30 AM
文章主题: Re: 委科學家成功以Wi-Fi連結相距382公里的電腦
這應該是為了適應第三世界開發中國家的應用環境而想出的變通方案,這倒是不失為有機會可普及於偏遠地區讓貧困人民使用的傳輸方式,也算是一件功德。現在美國想要把WiMAX變成是3G以及後3G通訊的主流規格,10月份的ITU大會中各國就會針對此議題進行辯論。看起來委內瑞拉向左轉之後,不僅是在石油經濟以及國際政治上,在無線通訊標準應用這一塊是不是也要跟美國來較量一下?
检视会员个人资料个人资料 回复文章 回顶端

Tommy Chung
(不在在线)
nbsp;
来自: 美加
文章: 1102

发 表 于: 2010.07.30 11:39:42 AM
文章主题: Re: 委科學家成功以Wi-Fi連結相距382公里的電腦

NetJets begins Aircell in-flight WiFi installations, won't stop anytime soon

检视会员个人资料个人资料 回复文章 回顶端

Tommy Chung
(不在在线)
nbsp;
来自: 美加
文章: 1102

发 表 于: 2010.08.16 12:04:41 PM
文章主题: Re: 委科學家成功以Wi-Fi連結相距382公里的電腦
检视会员个人资料个人资料 回复文章 回顶端

Tommy Chung
(不在在线)
nbsp;
来自: 美加
文章: 1102

发 表 于: 2010.09.16 11:15:55 AM
文章主题: Re: 委科學家成功以Wi-Fi連結相距382公里的電腦

FCC heralds a new era of 'super Wi-Fi'

"Super Wi-Fi," if adopted by a federal commission on Thursday, would make it easier to find wireless internet connections.

(CNN) -- It's more powerful than your current home network -- able to leap through tall buildings from a single port.

Look, up in the sky.

It's "SUPER Wi-Fi!"

At least that's what U.S. Federal Communications Commission Chairman Julius Genachowski is calling a new class of bigger-faster-better internet connections, which could jump from fiction to reality after a commission vote on September 23.

Genachowski says "super Wi-Fi," which he also refers to as "Wi-Fi on steroids," may spark a technological revolution in the U.S.

"The spectrum allows signals to travel further, to go through walls, to [transfer] more information -- so it's very robust," he said in an interview with CNN.com. "Super Wi-Fi has extraordinary potential. What's as exciting is we have a new platform for innovation and we can't anticipate what will happen next."

The souped-up system could result in wireless internet connections coming to rural areas, fewer "dead zones" in Wi-Fi networks and the ability to transfer large files easily between machines and computers in hospitals, the FCC says.

Cities might also be able to use the larger Wi-Fi networks to offer up public wireless internet hot spots and perform such tasks as remotely monitoring infrastructure and water quality.

The changes would come about if the FCC votes to open up some of the "white space" between TV channels for use by anyone.

That spectrum allows for fast file transfers over areas that are several times as large as traditional Wi-Fi networks, which are used in many homes to connect computers, printers and mobiles phones to the internet.

If freeing up "vacant airwaves" is approved, it would be the first time since 1985 that the FCC has made new chunks of the wireless spectrum available for unlicensed use.

"This is going to be the first release of unlicensed spectrum in over 25 years," Genachowski said. "The last time we did this it led to Wi-Fi. It led to a multibillion-dollar industry and extraordinary benefits that we experience every day.

"We believe that history can repeat itself, and unlicensed spectrum will catalyze private investment -- it will create a new platform for innovators and entrepreneurs to develop new and exciting products for the public."

In addition to Wi-Fi, the 1985 spectrum change paved the way for wireless remote controls on televisions, baby monitors, wireless microphones and other gadgets.

Not everyone has been excited about the FCC's super Wi-Fi proposal, however.

Some broadcast groups as well as those who use the wireless spectrum to power microphones have criticized the new Wi-Fi plans.

The National Association of Broadcasters, however, said in an e-mail to CNN that the group "is working constructively with the FCC in hopes that the agency adopts final 'white spaces' rules that preserve the ability of local and network broadcasters to deliver interference-free television."

Jeff Evans, deputy director of the Georgia Tech Research Institute's telecommunications lab, said it appears that most technical issues with the wireless spectrum have been worked out.

The freeing up of the spectrum, however, will require concessions from theater operators and churches that use wireless microphones. They likely will have to switch wireless frequencies, he said.

Still, Evans said, the move to super Wi-Fi would be a good one.

"It should allow you to penetrate through just about any building -- and multiple walls," he said. "And instead of transmitting, say, a half-mile outdoors, you should be able to go two or three miles."

A common complaint about current Wi-Fi is that it doesn't work in all parts of a building and that the signals are sometimes so weak that they drop frequently.

On a technical level, the difference between super Wi-Fi and current Wi-Fi signals is that they travel at different frequencies, Evans said.

Old Wi-Fi is a 2.4-GHz signal, which is a shorter wavelength than super Wi-Fi, which will operate at several longer wavelengths in the TV spectrum.

Those frequencies gives the new Wi-Fi its espoused superpowers, he said.

"The wavelength is much longer and it's not attenuated nearly as much -- it's not absorbed as much by the atmosphere when you're transmitting, and it's also not absorbed by the buildings as much," Evans said.

Five or so super-Wi-Fi hotspots might be able to provide internet service to a small downtown area, he said. But it may be two or more years before such applications are available to consumers. It will take time for gadget and antenna makers to adjust to the new standards, he said.

Genachowski, the FCC chairman, said super Wi-Fi may be rolled out more heavily in some areas than others.

In dense cities where many groups are already using wireless signals, for example, super Wi-Fi may not be as prominent as in rural areas.

Charles Golvin, an analyst at Forrester Research, said the FCC's plan could bring high-speed internet connections to new groups of people.

"It's taking an unused, or fallow, resource and making it available to help it address one of the significant challenges we as a society face," he said.

But, he added, the concept may not be economical. And, at least at first, it may not be helpful to people with mobile devices -- like smartphones and laptops -- who want to be able to get on the internet from anywhere.

"You're not going to have mobile phones and laptops that allow you to get in a taxi and go and be online as you're going to the airport and things like that," he said

The FCC is already testing the concept of super Wi-Fi in a few places.

The commission says the technology has been used to bring broadband internet to a school in rural Claudeville, Virginia, to add a public Wi-Fi network in Wilmington, North Carolina, and obtain data about the "smart grid" electricity infrastructure in Plumas County, California.

(CNN News)

检视会员个人资料个人资料 回复文章 回顶端
  相关讨论
MHL聯盟:用最簡單的方式 解決最複雜的問題
HanGee 改變台灣產業的夢想就此開始
HanGee 改變台灣產業的夢想就此開始
HanGee 改變台灣產業的夢想就此開始
HanGee 改變台灣產業的夢想就此開始
  相关新闻
从创新到落地!精诚AGP携手8家新创抢攻企业AI商机
Rohde & Schwarz 行动通讯测试高峰会聚焦无线通讯最新发展 - 现已提供线上回放
精诚「Carbon EnVision云端碳管理系统」获台湾精品奖银质奖 善尽企业永续责任 赚有意义的钱
善用「科技行善」力量 精诚集团旗下奇唯科技荣获「IT Matters 社会影响力产品奖」
工业AI与企业转向RAG趋势 将重塑2025年亚太暨日本地区IT业务环境
  相关文章
您需要了解的五种软体授权条款
使用PyANSYS探索及优化设计
能耗个个击破 5G与AI的节能之战
为AI注入理解力
深度资讯编码架构之探讨
刊登廣告 新聞信箱 读者信箱 著作權聲明 隱私權聲明 本站介紹

Copyright ©1999-2024 远播信息股份有限公司版权所有 Powered by O3
地址:台北市中山北路三段29号11楼 / 电话 (02)2585-5526 / E-Mail: webmaster@ctimes.com.tw