Some one sent email asking what is the maximum practical range for 802.11n, and how I can get the most range?

Wireless range is difficult to define because it is influenced by various factors. The big variable is data rate. For example, it’s possible to extend the range by lowering the data rate. Data rates and effective ranges are also impacted by electrical and physical interference to the wireless radio signal. This includes interference from wireless telephones operating in the 2.4GHz or 5GHz frequencies used by
different 802.11 standards, along with physical interference, such as walls, floors, windows, and other obstructions between the wireless NIC and the wireless access point. Even manufacturers don’t list absolute ranges. Instead, they note maximum ranges that the devices are theoretically capable of reaching.

From a more practical standpoint, 802.11n should easily provide wireless coverage at excellent data rates, about 250Mbps or more throughout your entire house, though it’s usually a good idea to locate
the wireless router centrally in the house. Outside, you’ll find that you can probably maintain your 802.11n connection to a range of about 200 meters or more. Just remember that the signal strength and the
resulting data speeds will fall off as you move farther away.

You can get the most range by minimizing interference and physical obstacles between your wireless points. If you use cordless phones,
be sure that the phone operates outside of the 2.4GHz and 5GHz frequencies used by 802.11n.

The use of high-gain or directional antennas can also help maximize wireless range, but they will add cost to your wireless setup.

Tags: Wi-Fi, Wireless-G, Wireless

While Steve Jobs was showing off the iPhone and the Apple TV, Apple quietly introduced a new AirPort Extreme Base Station that supports 802.11n, a networking standard that works up to five times faster and at up to twice the range of the previous version. The new base station will be available around the same time as the Apple TV.

The new AirPort Extreme Base Station marks a radical design departure from its predecessors. While the older Base Stations had a squat, teardrop-shaped design, the new model features a beveled square shape similar to that of the Mac mini and the new Apple TV. It measures 6.5 inches square and 1.3 inches tall.

Based on a draft specification of the 802.11n standard, the new AirPort Extreme Base Station is backward-compatible with the earlier 802.11g standard and works with 802.11b- and 802.11a-based devices. 802.11n uses a technique known as multipleinput, multiple-output (MIMO) to achieve faster performance and a longer range. While 802.11n offers seamless connectivity with older products, the performance of an 802.11n network will slow down if you connect slower devices to it. Newer Macs specifically Core 2 Duo iMacs (excluding the 17-inch 1.83GHz model), Core 2 Duo MacBooks and MacBook Pros, and Mac Pros include compatible hardware, but it must be enabled through software that’s included with the new Base Station.

The Base Station also lets you share USB-based printers and hard disk drives with the network, and it can support a hub, so you can attach multiple devices. Software included with the device lets you create password-protected accounts or limit access to certain files and folders. The device itself can support as many as 50 users at once.

The D-Link RangeBooster N650 DIR-635 wireless router, D-Link’s first stab at networking gear based on the Draft 802.11n spec, does little to separate itself from the Draft N competition. (Vendors aren’t promising that Draft N hardware will work with final-spec 802.11n products but a firmware upgrade will probably bring Draft N products in line with the final spec.)

In terms of looks and connections, the DIR-635 is fairly standard. Three adjustable antennae protrude from the black-and-silver box, and the back of the router offers up the standard ports: four LAN jacks for hardwired connections, a WAN port for connecting the router to a modem, and one USB port.

Setup is straightforward. The included CD walks you through all the steps, from plugging in the cables to powering on and configuring network settings. A 90-page electronic manual further details the setup and configuration processes, and translates tech-speak into plain English. In an interesting move, D-Link in this router has done away with the familiar Wired Equivalent Privacy (WEP) security option, offering support for only Wi-Fi Protected Access (WPA) and WPA2.

In the tests, the DIR-635 beat all Draft N routers of short-range mixed-throughput test (at 10 feet) and in long-range test (200 feet), posting scores of 58.8Mbps and 41Mbps, respectively. It fell to the back of the pack, however, on maximum-throughput test (at 10 feet), with a score of 68.1Mbps.

D-Link backs the router with a one-year warranty, which pales in comparison to Linksys’ three-year policies and Belkin’s lifetime support. Still, phone support is available 24/7, or you can contact tech support via an online form.

Like the other draft-n routers, Buffalo’s Nfiniti Wireless-N Router and AP promises throughput five times faster than that of 802.11g. And though, like the others, it doesn’t quite live up to that promise, it’s nonetheless speedy.

Most routers offer a single-mode option, but the Nfiniti operates only in a mixed b/g/n mode, which means older-generation products on your network, such as 802.11b clients, can become network bottlenecks. Installing the router is simple and straightforward: the printed quick-start guide walks you through the steps of connecting the modem, a router, and a PC (via Ethernet cables) and powering up each component. The Buffalo AirStation Nfiniti router supports only Windows XP/2000/Me/98 SE operating systems; Mac and Unix users are out of luck.

Through the configuration utility, you can access the Buffalo’s proprietary network-setup protocol. By pressing the button on the router and the corresponding button or virtual button, in the case of network adapters, you should be able to initiate a wireless network connection automatically.

The Nfiniti offers competitive performance. In mixed-mode test at 10 feet, the router beat the competition with an impressive data rate of 60.2Mbps. At 200 feet, it still delivered a very satisfactory 38.2Mbps. Still, its performance falls short of the promise of 802.11n, the first draft of which specifies a maximum throughput of 270Mbps. Because of this, hold back on buying Draft-N gear and wait until the 802.11n specification is finalized in mid-2007 to see how performance shakes out.

Two different groups testing new wireless products based on a draft standard of next-generation Wi-Fi technology are cautioning consumers against buying pre-standard networking gear. The Farpoint Group and the technology trade publication eWeek have released the results of tests on new products using draft versions of the 802.11n standard. While eWeek’s assessment was not nearly as negative as the Farpoint Group’s, both groups concurred that it was still too soon for consumers to buy products using 802.11n.

The 802.11n standard, which should be finalized early next year, will allow notebook users to connect to wireless access points at speeds much faster than what’s currently available with 802.11g technology.The 802.11n standard will use multiple-input-multiple-output (MIMO) technology, which is expected to improve range and throughput.

At the same time, eWeek tested Linksys’ new WRT300N Wireless-N Broadband Router and the WPC300N Wireless-N Notebook Adapter. It found that while Linksys’ draft-802.11n gear was the fastest wireless equipment the magazine had tested to date at short distances, its performance at a 50-foot range was disappointing.bk_keywords:802.11n.

In an early salvo to prove that wireless LAN equipment based on Draft 1.0 of the 802.11n standard is not only extremely fast but also interoperable among different vendor implementations, Broadcom and Atheros announced on May 31 the results of a month’s worth of interoperability testing. Gear based on each company’s chip sets does play nice together, given the right circumstances but consumers should take that info with a grain of salt.

The tests aimed to prove chip-set interoperability given several mandatory elements of the draft standard, as well as one optional element.

Tests were conducted using a single Atheros client adapter associated to a Broadcom access point, and using a single Broadcom client associated to an Atheros access point. Using Ixia’s IxChariot, testers gathered full-duplex bandwidth measurements for each testbed, finding each combo able to surpass 100M bps of full-duplex traffic.

It is hard to gauge what these tests mean in the grand scheme of things, since they represent a narrow slice in time with findings for specifically detailed firmware and software revisions. In the case of the Broadcom gear, the firmware under test was actually an earlier revision than the one eWeek Labs used for last month’s review of Linksys’ draft-802.11n-based WRT300N. eWeek also learned that the Broadcom firmware has revved twice, so these interoperability tests are based on old technology, indeed.

Given the lack of data for more current revisions, not to mention the complete lack of testing of products from another draft-802.11n chip-set vendor : Marvell, users shouldn’t expect interoperability to come quite so easily in a multivendor home network.

source: www.eweek.com
bk_keywords:802.11n

You may have seen those new wireless routers from Linksys, Netgear, and others products promising true 802.11n capabilities. These wireless networks are certainly fast and extend further than most others, but don’t fall for the claims of interoperability and compatibility with future products and with the future spec. Although they comply with an 802.11n draft proposal, there’s no guarantee that anything you buy today will be upgradable to full compatibility, once the IEEE finalizes this wireless networking standard.

So is now a good time to buy these products? If you’re setting up a new wireless network, you should know that while non-standard “draft-n” products are fast and work better around walls and through ceilings than older gear, there is a high premium for this. You’ll have to buy “802.11n” routers and cards for all your computers from the same company to ensure you get the speed and range benefits. 802.11g and 802.11b devices with built-in radios like the excellent SoundBridge Radio will work no better on these draft-n networks.

So, the best action is to wait. Get a cheap 802.11g router like the Linksys WRT54G, and follow this guide to extend your wireless coverage. Need better coverage at home? Add an inexpensive access point, and follow 10 tips for improving your wireless network. It works great, and you don’t have to worry about replacing networking cards in all the computers in future.

Many of you have tested wireless networking gear that delivers over 100mbps already, but at present that speed entails a sacrifice: These superfast wireless products don’t adhere to the up-coming 802.11n standard. Although the first draft specification for that standard was approved in January 2006, this next stage in Wi-Fi’s evolution still has a long way to go. The final 11n standard won’t be approved until September 2007.

Don’t depend on vendors’ claims of firmware upgradability to the final 802.11n specification. If compatibility is a concern, stick with your 11g hardware, or cross your fingers and buy all your new gear from one manufacturer.

Rivalry between Wi-Fi chip providers reached new levels of confusion at 3GSM when Broadcom announced unofficially that it had the first chips to truly implement the next-generation IEEE 802.11n standard, which is still only in draft form. The announcement by chief technology officer Henry Samueli came during an impressive round of Broadcom product releases, including a new modular mobile platform called Cellairity.

Technology analysts had warned companies to be cautious of buying products claiming to be 11n before the standard is ratified. But Samueli denied Broadcom was jumping the gun. He claimed: ‘The spec is all but nailed down, and we can be 99 per cent certain our implementation is the one that the IEEE will go with, and will be what the Wifi standard for multiple-input multiple-output (MIMO) will become.’

His statement follows a year of obscure political wrangling among industry groups anxious to get their own pet design approved as the 11n standard. The argument became more heated after Airgo predicted that its technology would be adopted. The conflict continued when tests by a US website claimed an Airgo-based ‘pre-11n’ Netgear RM240 router could quash legacy 11g signals when using channel 6.