美国在大学校园测试空白频段“超级Wi-Fi”

美国西维吉尼亚大学 (West Virginia University)日前宣布，该校成为美国首个获准使用所谓“空白频段 (white spaces)”──电视广播频道转向数字化之后闲置的频段──的大学，能为校园与邻近的偏远地区提供无线宽带网络接取服务。 西维吉尼亚大学与一个拥有500多名成员、包含高等院校与科技业者(Google、Microsoft等)的团体“改善网际网路区域联盟(Advanced Internet Regions consortium，AIR.U)合作进行试运转计划，其初始目标是在不同的大学社区规划并布署数个试验网路，并在空白频段设备在2013逐渐普及的同时，针对快速布建可永续发展的下一代无线网路订定蓝图。” 上述计划的第一阶段，是在西维吉尼亚大学的交通运输系统PRT (Personal Rapid Transit，编按：类似捷运、轻轨电车)──拥有73部车厢，每日运量达1万5,000人次──布建供该校学生与教职员使用的免费Wi-Fi网路。西维吉尼亚大学资讯长John Campbell表示，以校园为测试据点进行无线连结性与宽频网路覆盖率的改善，可望为西维吉尼亚州众多仍缺乏宽频网路的区域提供有效的解决方案。 将在西维吉尼亚大学布建的无线宽频网路技术又称为“超级Wi-Fi (Super Wi-Fi)”，这个名词是美国联邦通讯委员会( FCC )所创造，意图在大都会与偏远地区打造新一代的长距离无线网络接取方案；不过该技术称之为“Wi-Fi”是有争议的，因为Super Wi-Fi与现有的2.4GHz频段Wi-Fi技术其实并不相容。 Super Wi-Fi所使用的是过去类比电视广播所使用的低频频段，必须使用与市面上Wi-Fi不同的无线电；目前针对空白频段所订定的标准有二，包括IEEE8021.11af 与IEEE802.22 。 有一些批评者认为，Super Wi-Fi根本没有什么“超级”之处，与号称速率将近1Gbps的最新Wi-Fi标准802.11ac相较，Super Wi-Fi的速率仅达29Mbps。但是因为Super Wi-Fi采用较低频段，在穿透障碍物与覆盖范围距离方面的表现较佳。 FCC在2012年9月提案奖励频谱拍卖，引发产业界人士与媒体对其频谱规划、空白频段如何使用以及Super Wi-Fi如何与频谱规划搭配等议题的争论与疑问。其实FCC在谈到空白频段运作之免牌照设备时，将频谱分为两种不同型态。 该机构将电视频谱的空白频段视为“Super Wi-Fi与针对社区、特别是偏远区域提供之无线宽频服务等新一代产品”的发展机会；而各方争抢的原属电视广播空白频段，主要是在700MHz，这个频段将继续开放免牌照使用。至于规划中的新频谱拍卖(预定2014年展开)，主要是锁定600MHz频段；理论上，这将为无牌照使用添加新的开放频谱。 此外FCC正考虑释放37频道(608 ~614 MHz)，以及部份在有牌照频谱之间的所谓“保护频段(guard bands)”，将之纳入空白频段规则中；据了解，此举将可最小化空白频段的干扰问题。FCC的提案中表示： “FCC的提案将为免牌照设备提供一定数量的频谱；该类频谱将有很大一部分是提供全国使用，而其重要性在于在许多主要市场的电视频道并没有空白频段或是空间有限。透过此提案，FCC期望能推动新产品、新服务的创新，包括为整个国家提升无线宽频服务的覆盖率。” 本文授权编译自EE Times，版权所有，谢绝转载 本文下一页：不支持Super Wi-Fi的人怎么看

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{pagination} 总之无论是有牌照使用者(例如移动通信运营商)以及无牌照使用者(包括Wi-Fi与蓝牙等无线设备供应商)，都对空白频段虎视眈眈。 不支持Super Wi-Fi的人认为，空白频段(以及未来可能在频谱拍卖中添加的开放频段)最好用以纾解目前的频宽不足问题。Super Wi-Fi的支持者则相信，AIR.U所推动的计划是让偏远地区取得无线宽频网路、又不用支付移动电话月租费的最好方式。 如Super Wi-Fi技术开发商Declaration Networks Group (DNG)首席执行官、AIR.U共同发起人Bob Nichols表示，Super Wi-Fi是一种低成本、可扩展的高容量无线网路技术，该公司期望能引领风潮，推出一种能复制到全国各乡镇城市，提供永续性经营模式的替代性宽频新方案。 DNG协助西维吉尼亚大学管理建置Super Wi-Fi测试网路，西维吉尼亚州远程运算网路(West Virginia Network for Telecomputing) 则为该测试网路提供光纤网际网路骨干；此外一家来自矽谷的新创公司Adaptrum，则是该测试网路的空白频段设备供应商。 本文授权编译自EE Times，版权所有，谢绝转载 编译：Judith Cheng 参考英文原文：'Super WiFi' Comes to WVU，by Junko Yoshida

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• Wi-Fi联盟开通11ac认证，支持产品类型多元化Pl9esmc

{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.