针对在部署高速无线局域网(WLAN)的过程中面临的功耗和其他问题,在Interop Las Vegas 2008上,各个供应商以此为目标积极应对。

Wi-Fi技术为WLAN带来了类似有线以太网一样的性能,但是,把移动设备连接到网络的接入点(AP)需要的功率一般来说比学校或商业上较老式的以太网供电系统(PoE)能够提供的功率更大。因客户们不愿意革新其基础设施,所以,无法从较慢的技术转移出来,为此,供应商要采取更具有创造性的解决方案。

例如,据博通公司透露,该公司计划展示一款新的实现接入点功能的片上系统,它消耗的功率是其它芯片组的一半。BCM4342是一款比90纳米处理器集成了更多晶体管的65纳米处理器,从而实现了更好的性能-功率比。该数字指的是提升微处理器性能所需要的晶体管的规模。

因此,最新的芯片组使接入点有可能利用现有的PoE基础设施在2.4 GHz和5 GHz射频频段同时工作,博通公司高级产品线经理Michael Powell表示。

运行双射频设备的能力是至关重要的,因为它们能够完全利用所有的的性能,如对多数据流的支持。老式的技术仅仅支持一个数据流。

这对于AP设备制造商来说是好消息,过去,它们必须做出折中以绕过功耗问题,如在单一射频系统中传递、自动关闭一些服务、采用两条PoE电缆或牺牲传输距离等等。博通公司宣称,在内建新处理器的接入点中不必采用那些折中。

博通公司表示,BCM4342在单一硅片上集成了媒体接入控制器、基带处理器、2.4 GHz和5 GHz射频以及其它WLAN组件。这就把WLAN子系统所需要的元器件的数量减少了2/3,从而进一步降低了制造商的物料成本。

IEEE有望在2009年3月最终确定现行标准的草案,并有望在09年12月出版该标准。然而,硬件制造商现在正在推出各种产品,因此,希望最终版本的标准与现行标准草案差异不大。

各个组织有兴趣向新技术转移,因为它提供可媲美有线以太网LAN的性能,与此同时,为终端用户在工作场所周围移动提供更大的灵活性。此外,该技术可以通过双模蜂窝电话实现VoIP通话,从而降低话费。

Aruba Networks公司表示,通过下载软件来引入可支持更快技术的接入点,从而使得向的转移更为容易。新的AP-124ABG和AP-125ABG可以被设置为支持,但是,当公司、学校、医院以及其它公共机构准备好做切换时,可以通过网络进行升级。在Interop上将要亮相的新产品预计在夏季开始时付运。报价尚未透露。

利用新的硬件,Aruba计划在Interop上推出其无线网络管理软件套件的升级版,其中,增加了对网络的支持以及在有线网络内进行监控的功能。

AirWave Wireless Management Suite 6可以被插入第三方IT服务管理软件之中,如BMC公司的Remedy软件之中,以便增加跟踪功能,并在无线网络上解决最终用户面临的问题。这个升级版软件还提供新的一组报告并监测观察,以确定一个无线网络何时逼近其容量,以便用户能够更好地管理所需要的扩展。

帮助向新技术的转移

在升级版软件中的一个关键功能就是能够监测有线网络的硬件,如路由器、交换机、确权服务器以及管理服务器,这些设备均对WLAN的性能有一定的影响。该功能有望提供更为全面的网络分析以及更为精确的诊断。

对于签订了服务合同的Aruba客户,获得本月付运的新产品将不需要额外费用,Aruba公司战略市场营销领导人Michael Tennefoss透露,起价不低于6千美元。

Aerohive Networks计划推出的一种接入点不需要昂贵的中控控制器来管理流量。此外,该设备采用公司专有的SmartPoE技术来检测网络上的功率水平,并作出必需的调节。如果客户选择在基础设施上不做折中地传递所需要的功率,该设备还具有两个PoE口。

Aerohive宣称,这种不需要控制器的WLAN架构消除了因流量通过控制器而导致的带宽、延迟和抖动瓶颈。该公司还表示,它把控制器功能分布在接入点上的策略使得网络更为有弹性和可扩展性。

Aerohive计划提供三款接入点,HiveAP 320被构建用于室内应用,HiveAP 340被构建用于室内应用,而HiveAP 380被构建用于室外应用。前两款产品预计在7月付运,而后一种产品预计在第四季度交付使用。

针对预算紧张但需要更高设备性能的买家,Ruckus Wireless计划展示一种单射频 ZoneFlex 7942接入点。该设备的配置是利用跟Ruckus ZoneDirector控制器一道付运的、基于网络的向导完成的。

ZoneFlex 7942同时支持高达100个用户或20个并发语音呼叫,Ruckus表示,设备成本大约为700美元。

最后,Trapeze Networks公司计划展示MP-432双射频AP,该公司宣称它在 PoE连接上能够支持性能。后者就是在网络上所采用的。该公司宣称其设备还支持用于网络的、即将出现的 PoE标准。MP-432目前以1300美元供货。

翻页查看英文原文:

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.