美國(guó)西維吉尼亞大學(xué) (West Virginia University)日前宣布，該校成為美國(guó)首個(gè)獲準(zhǔn)使用所謂“空白頻段 (white spaces)”──電視廣播頻道轉(zhuǎn)向數(shù)字化之后閑置的頻段──的大學(xué)，能為校園與鄰近的偏遠(yuǎn)地區(qū)提供無(wú)線寬帶網(wǎng)絡(luò)接取服務(wù)。 西維吉尼亞大學(xué)與一個(gè)擁有500多名成員、包含高等院校與科技業(yè)者(Google、Microsoft等)的團(tuán)體“改善網(wǎng)際網(wǎng)路區(qū)域聯(lián)盟(Advanced Internet Regions consortium，AIR.U)合作進(jìn)行試運(yùn)轉(zhuǎn)計(jì)劃，其初始目標(biāo)是在不同的大學(xué)社區(qū)規(guī)劃并布署數(shù)個(gè)試驗(yàn)網(wǎng)路，并在空白頻段設(shè)備在2013逐漸普及的同時(shí)，針對(duì)快速布建可永續(xù)發(fā)展的下一代無(wú)線網(wǎng)路訂定藍(lán)圖?！? 上述計(jì)劃的第一階段，是在西維吉尼亞大學(xué)的交通運(yùn)輸系統(tǒng)PRT (Personal Rapid Transit，編按：類似捷運(yùn)、輕軌電車)──擁有73部車廂，每日運(yùn)量達(dá)1萬(wàn)5,000人次──布建供該校學(xué)生與教職員使用的免費(fèi)Wi-Fi網(wǎng)路。西維吉尼亞大學(xué)資訊長(zhǎng)John Campbell表示，以校園為測(cè)試據(jù)點(diǎn)進(jìn)行無(wú)線連結(jié)性與寬頻網(wǎng)路覆蓋率的改善，可望為西維吉尼亞州眾多仍缺乏寬頻網(wǎng)路的區(qū)域提供有效的解決方案。 將在西維吉尼亞大學(xué)布建的無(wú)線寬頻網(wǎng)路技術(shù)又稱為“超級(jí)Wi-Fi (Super Wi-Fi)”，這個(gè)名詞是美國(guó)聯(lián)邦通訊委員會(huì)( FCC )所創(chuàng)造，意圖在大都會(huì)與偏遠(yuǎn)地區(qū)打造新一代的長(zhǎng)距離無(wú)線網(wǎng)絡(luò)接取方案；不過(guò)該技術(shù)稱之為“Wi-Fi”是有爭(zhēng)議的，因?yàn)镾uper Wi-Fi與現(xiàn)有的2.4GHz頻段Wi-Fi技術(shù)其實(shí)并不相容。 Super Wi-Fi所使用的是過(guò)去類比電視廣播所使用的低頻頻段，必須使用與市面上Wi-Fi不同的無(wú)線電；目前針對(duì)空白頻段所訂定的標(biāo)準(zhǔn)有二，包括IEEE8021.11af 與IEEE802.22 。 有一些批評(píng)者認(rèn)為，Super Wi-Fi根本沒(méi)有什么“超級(jí)”之處，與號(hào)稱速率將近1Gbps的最新Wi-Fi標(biāo)準(zhǔn)802.11ac相較，Super Wi-Fi的速率僅達(dá)29Mbps。但是因?yàn)镾uper Wi-Fi采用較低頻段，在穿透障礙物與覆蓋范圍距離方面的表現(xiàn)較佳。 FCC在2012年9月提案獎(jiǎng)勵(lì)頻譜拍賣，引發(fā)產(chǎn)業(yè)界人士與媒體對(duì)其頻譜規(guī)劃、空白頻段如何使用以及Super Wi-Fi如何與頻譜規(guī)劃搭配等議題的爭(zhēng)論與疑問(wèn)。其實(shí)FCC在談到空白頻段運(yùn)作之免牌照設(shè)備時(shí)，將頻譜分為兩種不同型態(tài)。 該機(jī)構(gòu)將電視頻譜的空白頻段視為“Super Wi-Fi與針對(duì)社區(qū)、特別是偏遠(yuǎn)區(qū)域提供之無(wú)線寬頻服務(wù)等新一代產(chǎn)品”的發(fā)展機(jī)會(huì)；而各方爭(zhēng)搶的原屬電視廣播空白頻段，主要是在700MHz，這個(gè)頻段將繼續(xù)開(kāi)放免牌照使用。至于規(guī)劃中的新頻譜拍賣(預(yù)定2014年展開(kāi))，主要是鎖定600MHz頻段；理論上，這將為無(wú)牌照使用添加新的開(kāi)放頻譜。 此外FCC正考慮釋放37頻道(608 ~614 MHz)，以及部份在有牌照頻譜之間的所謂“保護(hù)頻段(guard bands)”，將之納入空白頻段規(guī)則中；據(jù)了解，此舉將可最小化空白頻段的干擾問(wèn)題。FCC的提案中表示： “FCC的提案將為免牌照設(shè)備提供一定數(shù)量的頻譜；該類頻譜將有很大一部分是提供全國(guó)使用，而其重要性在于在許多主要市場(chǎng)的電視頻道并沒(méi)有空白頻段或是空間有限。透過(guò)此提案，F(xiàn)CC期望能推動(dòng)新產(chǎn)品、新服務(wù)的創(chuàng)新，包括為整個(gè)國(guó)家提升無(wú)線寬頻服務(wù)的覆蓋率?！? 本文授權(quán)編譯自EE Times，版權(quán)所有，謝絕轉(zhuǎn)載 本文下一頁(yè)：不支持Super Wi-Fi的人怎么看

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{pagination} 總之無(wú)論是有牌照使用者(例如移動(dòng)通信運(yùn)營(yíng)商)以及無(wú)牌照使用者(包括Wi-Fi與藍(lán)牙等無(wú)線設(shè)備供應(yīng)商)，都對(duì)空白頻段虎視眈眈。 不支持Super Wi-Fi的人認(rèn)為，空白頻段(以及未來(lái)可能在頻譜拍賣中添加的開(kāi)放頻段)最好用以紓解目前的頻寬不足問(wèn)題。Super Wi-Fi的支持者則相信，AIR.U所推動(dòng)的計(jì)劃是讓偏遠(yuǎn)地區(qū)取得無(wú)線寬頻網(wǎng)路、又不用支付移動(dòng)電話月租費(fèi)的最好方式。 如Super Wi-Fi技術(shù)開(kāi)發(fā)商Declaration Networks Group (DNG)首席執(zhí)行官、AIR.U共同發(fā)起人Bob Nichols表示，Super Wi-Fi是一種低成本、可擴(kuò)展的高容量無(wú)線網(wǎng)路技術(shù)，該公司期望能引領(lǐng)風(fēng)潮，推出一種能復(fù)制到全國(guó)各鄉(xiāng)鎮(zhèn)城市，提供永續(xù)性經(jīng)營(yíng)模式的替代性寬頻新方案。 DNG協(xié)助西維吉尼亞大學(xué)管理建置Super Wi-Fi測(cè)試網(wǎng)路，西維吉尼亞州遠(yuǎn)程運(yùn)算網(wǎng)路(West Virginia Network for Telecomputing) 則為該測(cè)試網(wǎng)路提供光纖網(wǎng)際網(wǎng)路骨干；此外一家來(lái)自矽谷的新創(chuàng)公司Adaptrum，則是該測(cè)試網(wǎng)路的空白頻段設(shè)備供應(yīng)商。 本文授權(quán)編譯自EE Times，版權(quán)所有，謝絕轉(zhuǎn)載 編譯：Judith Cheng 參考英文原文：'Super WiFi' Comes to WVU，by Junko Yoshida

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{pagination} 'Super WiFi' Comes to WVU Junko Yoshida MADISON, Wis. — West Virginia University advanced the cause of offering expanded broadband access to underserved rural communities with the announcement Tuesday, July 9, that it became the first university in the United States to use low-frequency "white spaces" -- left empty by TV stations that have switched to digital broadcasting -- to provide wireless broadband coverage on the campus and nearby areas. The university rolled out the pilot program in partnership with the Advanced Internet Regions consortium (AIR.U), a group of more than 500 higher learning institutions and technology industry partners such as Google and Microsoft. The group's initial goal is "to plan and deploy several pilot networks in diverse university communities and create a roadmap for the rapid deployment of sustainable, next-generation wireless networks as White Space equipment becomes widely available in 2013," said the consortium in a statement last year. The initial phase of the network provides free public WiFi access for students and faculty on a 73-car tram system that transports some 15,000 riders daily, known as PRT, or Personal Rapid Transit. Improved wireless connectivity and broadband coverage, with the campus as a test site, "may well offer a solution for the many West Virginia communities where broadband access continues to be an issue," West Virginia University chief information officer John Campbell said in a statement. Pros and cons of "Super WiFi" The wireless broadband network offered at West Virginia University is called "Super WiFi" -- a term originally coined by the Federal Communications Commission with the intention of creating new longer-distance wireless Internet access in both metropolitan and rural areas. The terminology, however, is somewhat controversial, because Super WiFi isn't compatible with WiFi (which is trademarked). Unlike WiFi, which uses a 2.4 GHz radio frequency, Super WiFi uses lower-frequency white spaces between television channels. The result is that Super WiFi must use a different radio from conventional WiFi, and currently two different standards are being developed for the white-space spectrum: IEEE8021.11af and IEEE802.22. Critics also claim that there is nothing "super" about Super WiFi. Compared to the latest WiFi standard such as IEEE 802.11ac, designed to deliver throughput rates close to 1 Gigabit per second in a base configuration, Super WiFi is reportedly slow -- limited to a peak rate of 29 megabits per second. However, Super WiFi signals, at lower frequencies, are better at broaching thick walls and covering larger expanses. FCC spectrum auction In conjunction with the FCC's incentive spectrum auction proposal, launched in September 2012, the industry and the media have stirred both debate and confusions over the FCC's spectrum plan, how best to use the white spaces, and how Super WiFi might fit into the picture. Just to clarify, the FCC is talking of two types of spectrum, when it discusses unlicensed devices to operate in "white spaces." The agency sees the white spaces in the TV spectrum as an opportunity for "a new generation of products such as Super WiFi and wireless broadband services for communities, particularly in rural areas." First, there is the existing TV white space spectrum that has been fought over -- generally in the 700 MHz realm. This will remain available for unlicensed uses. Second, as part of the discussion on the planned new spectrum auction (scheduled in 2014) focused in the 600 MHz block, FCC is proposing that the new auction should, in theory, add additional open spectrum for unlicensed use. The FCC is specifically looking at freeing up channel 37 (608 to 614 MHz), and portions of the so-called "guard bands" between licensed spectrum chunks, that they would like to "add" to the existing white space rules. Such moves are said to minimize interference problems in the white space. The agency said: The FCC's proposals will enable a substantial amount of spectrum use by unlicensed devices. A significant portion of this spectrum will be available on a nationwide basis, which is important because there currently is little or no white space in the TV bands in parts of many major markets. In making these proposals, the FCC seeks to promote greater innovation in new products and services, including increased access for wireless broadband services across the country. Stakeholders vying for the coveted white space spectrum include licensed users (current cellular network operators) and unlicensed users (offering products based on Wi-Fi, Bluetooth and others). Opponents to Super Wi-Fi argue that white space (and the additional open spectrum that becomes available as part of the spectrum auction) is best used to ease bandwidth problems. Advocates of Super Wi-Fi, meanwhile, believe the initiative promoted by AIR.U is the best way to connect underserved communities with wireless broadband access without having to pay a monthly cellphone bill. Bob Nichols, CEO of Declaration Networks Group (DNG), LLC and AIR.U co-founder, said in a statement, "Super Wi-Fi presents a lower-cost, scalable approachto deliver high capacity wireless networks." He explained that the company hopes to "lead the way for a new broadband alternative to provide sustainable models that can be replicated and extended to towns and cities nationwide." Technology contributors Helping to enable West Virginia University to become the Super Wi-Fi test site are: AIR.U co-founder Declaration Networks Group to manage network deployment; the West Virginia Network for Telecomputing to provide the fiber optic Internet backhaul for the network: and Adaptrum Inc., a San Jose-based start-up offering white space equipment designed to operate on vacant TV channels. Microsoft and Google both provided early support for AIR.U's overall effort to spur innovation to upgrade the broadband available to underserved campuses and their surrounding communities. West Virginia Univ. stated in its press release: Because the unique propagation characteristics of TV band spectrum enables networks to broadcast Wi-Fi connections over several miles and over hilly and forested terrain, the FCC describes unlicensed access to vacant TV channels as enabling 'Super Wi-Fi' services. For example, WVU can add additional Wi-Fi hotspots in other locations around campus where students congregate or lack connectivity today. Future applications include public Wi-Fi access on the PRT cars and machine-to-machine wireless data links supporting control functions of the PRT System. This initial deployment, blanketing the WVU campus with Wi-Fi connectivity, will test equipment capabilities, system throughput and the performance of TV band frequencies in supporting broadband Internet applications.