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針對在部署高速無線局域網(WLAN)的過程中面臨的功耗和其他問題,在Interop Las Vegas 2008上,各個供應商以此為目標積極應對。

Wi-Fi技術為WLAN帶來了類似有線以太網一樣的性能,但是,把移動設備連接到網絡的接入點(AP)需要的功率一般來說比學校或商業上較老式的以太網供電系統(PoE)能夠提供的功率更大。因客戶們不愿意革新其基礎設施,所以,無法從較慢的技術轉移出來,為此,供應商要采取更具有創造性的解決方案。

例如,據博通公司透露,該公司計劃展示一款新的實現接入點功能的片上系統,它消耗的功率是其它芯片組的一半。BCM4342是一款比90納米處理器集成了更多晶體管的65納米處理器,從而實現了更好的性能-功率比。該數字指的是提升微處理器性能所需要的晶體管的規模。

因此,最新的芯片組使接入點有可能利用現有的PoE基礎設施在2.4 GHz和5 GHz射頻頻段同時工作,博通公司高級產品線經理Michael Powell表示。

運行雙射頻設備的能力是至關重要的,因為它們能夠完全利用所有的的性能,如對多數據流的支持。老式的技術僅僅支持一個數據流。

這對于AP設備制造商來說是好消息,過去,它們必須做出折中以繞過功耗問題,如在單一射頻系統中傳遞、自動關閉一些服務、采用兩條PoE電纜或犧牲傳輸距離等等。博通公司宣稱,在內建新處理器的接入點中不必采用那些折中。

博通公司表示,BCM4342在單一硅片上集成了媒體接入控制器、基帶處理器、2.4 GHz和5 GHz射頻以及其它WLAN組件。這就把WLAN子系統所需要的元器件的數量減少了2/3,從而進一步降低了制造商的物料成本。

IEEE有望在2009年3月最終確定現行標準的草案,并有望在09年12月出版該標準。然而,硬件制造商現在正在推出各種產品,因此,希望最終版本的標準與現行標準草案差異不大。

各個組織有興趣向新技術轉移,因為它提供可媲美有線以太網LAN的性能,與此同時,為終端用戶在工作場所周圍移動提供更大的靈活性。此外,該技術可以通過雙模蜂窩電話實現VoIP通話,從而降低話費。

Aruba Networks公司表示,通過下載軟件來引入可支持更快技術的接入點,從而使得向的轉移更為容易。新的AP-124ABG和AP-125ABG可以被設置為支持,但是,當公司、學校、醫院以及其它公共機構準備好做切換時,可以通過網絡進行升級。在Interop上將要亮相的新產品預計在夏季開始時付運。報價尚未透露。

利用新的硬件,Aruba計劃在Interop上推出其無線網絡管理軟件套件的升級版,其中,增加了對網絡的支持以及在有線網絡內進行監控的功能。

AirWave Wireless Management Suite 6可以被插入第三方IT服務管理軟件之中,如BMC公司的Remedy軟件之中,以便增加跟蹤功能,并在無線網絡上解決最終用戶面臨的問題。這個升級版軟件還提供新的一組報告并監測觀察,以確定一個無線網絡何時逼近其容量,以便用戶能夠更好地管理所需要的擴展。

幫助向新技術的轉移

在升級版軟件中的一個關鍵功能就是能夠監測有線網絡的硬件,如路由器、交換機、確權服務器以及管理服務器,這些設備均對WLAN的性能有一定的影響。該功能有望提供更為全面的網絡分析以及更為精確的診斷。

對于簽訂了服務合同的Aruba客戶,獲得本月付運的新產品將不需要額外費用,Aruba公司戰略市場營銷領導人Michael Tennefoss透露,起價不低于6千美元。

Aerohive Networks計劃推出的一種接入點不需要昂貴的中控控制器來管理流量。此外,該設備采用公司專有的SmartPoE技術來檢測網絡上的功率水平,并作出必需的調節。如果客戶選擇在基礎設施上不做折中地傳遞所需要的功率,該設備還具有兩個PoE口。

Aerohive宣稱,這種不需要控制器的WLAN架構消除了因流量通過控制器而導致的帶寬、延遲和抖動瓶頸。該公司還表示,它把控制器功能分布在接入點上的策略使得網絡更為有彈性和可擴展性。

Aerohive計劃提供三款接入點,HiveAP 320被構建用于室內應用,HiveAP 340被構建用于室內應用,而HiveAP 380被構建用于室外應用。前兩款產品預計在7月付運,而后一種產品預計在第四季度交付使用。

針對預算緊張但需要更高設備性能的買家,Ruckus Wireless計劃展示一種單射頻 ZoneFlex 7942接入點。該設備的配置是利用跟Ruckus ZoneDirector控制器一道付運的、基于網絡的向導完成的。

ZoneFlex 7942同時支持高達100個用戶或20個并發語音呼叫,Ruckus表示,設備成本大約為700美元。

最后,Trapeze Networks公司計劃展示MP-432雙射頻AP,該公司宣稱它在 PoE連接上能夠支持性能。后者就是在網絡上所采用的。該公司宣稱其設備還支持用于網絡的、即將出現的 PoE標準。MP-432目前以1300美元供貨。

翻頁查看英文原文:

Interop: Vendors tackle Wi-Fi troubles

Vendors at Interop Las Vegas 2008 are taking aim at the power-consumption problem faced by organizations deploying high-speed  wireless LANs.

The Wi-Fi technology brings wired Ethernet-like performance to WLANs, but the access points that connect mobile devices to the network typically use more power than a school's or business' older power over Ethernet system can deliver. With customers unwilling to overhaul their infrastructure to migrate from slower  technology, vendors are getting creative.

Broadcom, for example, plans to demonstrate a new system-on-a-chip for access points that uses half the power of other chipsets, according to the company. The BCM4342 is a 65-nanometer processor that packs more transistors than the typical 90-nm chip used today for a far better power-to-performance ratio. The numbers refer to the size of the transistors that drive microprocessors.

As a result the latest chipset makes it possible for access points to operate simultaneously on the 2.4 GHz and 5 GHz frequency radio bands using an existing PoE infrastructure, Michael Powell, senior product line manager for Broadcom, told InformationWeek.

Being able to run dual-radio devices is important because they are able to take full advantage of all of 's capabilities, such as support for multiple data streams. The older  technology supported only one data stream.

This is good news for access-point manufacturers that have had to make compromises to get around the power problem, such as delivering  in a single-radio system, automatically disabling some services, requiring two PoE cables, or sacrificing range. Broadcom claims those tradeoffs won't be necessary in access points built with its new processor.

BCM4342 combines an  medium access controller, a baseband processor, 2.4 GHz and 5 GHz radios and other WLAN components on a single silicon die, according to Broadcom. This reduces the number of components required for a WLAN subsystem by two-thirds, which lowers a manufacturer's bill of materials cost.

The IEEE is expected to finalize the current draft of the  standard in March 2009 with publication expected that December. Hardware manufacturers, however, are releasing products now, expecting the final version to not be much different than what's available today.

Organizations are interested in migrating to the new technology because it delivers performance comparable to a traditional wired Ethernet LAN, while providing end users with more flexibility in moving around the workplace. In addition, the technology can support voice over IP calls through dual-mode cellular phones, which could reduce telephone bills.

Aruba Networks says it's making the move to  easier by introducing access points that can be enabled for the faster technology through a software download. The new AP-124ABG and AP-125ABG support  out of the box, but can be upgraded over the network when companies, schools, hospitals and other institutions are ready to make the switch. The new products, which will be on display at Interop, are scheduled to ship early in the summer. Pricing was not disclosed.

Along with the new hardware, Aruba plans to introduce at Interop an upgrade of its wireless network management suite of software that adds support for  networks and the monitoring of hardware within a wired network.

AirWave Wireless Management Suite 6 can be plugged into third-party IT service management software, such as BMC's Remedy, in order to add tracking and resolution of end-user problems on a wireless network. The upgrade also offers a new set of reports and monitoring views to determine when a wireless network is approaching capacity, so users can better manage needed expansions.

Helping Migrate To New Technology

Another key new feature in the upgrade is the ability to monitor wired network hardware, such as routers, switches, authentication servers and management servers, which may have an impact on the performance of a WLAN. The feature is expected to provide more comprehensive network analysis and more accurate diagnostics.

The new product ships this month, and will be available at no additional charge to Aruba customers with service contracts. For new customers, pricing starts at less than $6,000, Michael Tennefoss, head of strategic marketing at Aruba, told InformationWeek.

Aerohive Networks plans to introduce a line of  access points that do not need expensive centralized controllers to manage traffic. In addition, the devices use the company's proprietary SmartPoE technology that detects the level of power on the network and makes the necessary adjustments. The devices also have two PoE ports if a customer chooses to deliver the needed power on an  infrastructure without making compromises.

Aerohive claims that its controller-less WLAN architecture eliminates bandwidth bottlenecks, latency and jitter that results from moving traffic through a controller. The company also said its strategy of distributing controller functions among the access points makes the network more resilient and scalable.

Aerohive plans to offer three  access points. The HiveAP 320 is built for indoor use, the HiveAP 340 for indoor-industrial use, and the HiveAP 380 for outdoor use. The first two are scheduled to ship in July, and the latter in the fourth quarter.

Ruckus Wireless plans to show off its one-radio,  ZoneFlex 7942 access point for organizations that want a higher performing  device, but are on a tight budget. Configuration of the device is done through a Web-based wizard that ships with the Ruckus ZoneDirector controller.

The ZoneFlex 7942 supports up to 100 simultaneous data users or 20 concurrent voice calls, according to Ruckus. The device costs about $700.

Finally, Trapeze Networks plans to demonstrate the MP-432, a dual-radio access point that the company claims can provide  capabilities on an  PoE connection. The latter standard is what's used on  networks. The company claims its device also supports the emerging  PoE standard for  networks. The MP-432 is available now for $1,300.