The promise of 802.11n is two-fold. First, by using a technology called "multiple-input, multiple-output" (MIMO), 11n is supposed to offer radically greater range -- up to four times the distance of 802.11g. Second, connection speeds of up to 300Mb/s are available to devices using the new standards.
There's only one problem with the 802.11n standard: It doesn't exist yet. The working group of the Institute of Electrical and Electronics Engineers (IEEE) that is responsible for defining Wi-Fi standards is still determining exactly what 802.11n is. In fact, the current estimate is that the standard won't be finished until mid-2007.
This hasn't stopped all the major Wi-Fi vendors from developing 802.11n products, however. How is this possible? Because before a standard is finalized, draft standards are released. A draft specification of 802.11n was produced by the working group in the spring of 2006, and that draft is what is being implemented in the products now being sold, which refer to themselves as "draft 802.11n" or "pre-N" products.
With that in mind, we sat down with the draft-N product line from Linksys, to see what it was capable of. We were provided with two PCMCIA adaptor cards (WPC300N) and a wireless router (WRT300N) for testing. The router looks pretty much like any wireless home router, except that in addition to the two stick antennas that an older router might sport, it also has a paddle-shaped antenna between other two. It also has 4 LAN Ethernet ports on the back to allow hardwired devices to run through the router.
Configuring the router will be no challenge for anyone who's ever set up a Wi-Fi hub before. The router comes with a setup disk that can run from a connected Windows PC, but it can also be configured via the standard web-browser interface. Naturally, it has the latest encryption protocols to keep your signal secure.
The adaptor is a standard PCMCIA card, which comes with a driver CD. Like many third-party adaptors, it has its own configuration management program that will co-opt the Windows Wi-Fi manager if you let it. In testing, the Linksys configuration program was both easy to use and reliable.
Of course, the real question is: How does it perform? To answer this question, we used two tests. The first is a benchmarking program called QCheck, which does nothing but time how long it takes to send data back and forth to a host system. For more of a real-world challenge, we also tried timing how long it took to copy a 1GB video file from a local server to the laptop.
To establish a theoretical maximum, we began by hooking the laptop directly up to the router with a cable. Using this method, we saw data rates of between 80 and 90 Mb/s, and transfer times around 3 minutes. Since the laptop has built-in 802.11g, and there were already existing 802.11g networks in the house, we were able to test all permutations (11g to 11g, 11n to 11g, 11g to 11n, and 11n to 11n.)
All of the 11g-based tests had about the same results, between 16 and 20 Mb/s using QCheck and just under 10 minutes to transfer the file. Then we asked the adaptor to connect to the router and were pleased to see that the tooltip for the wireless connection was indicating 300 Mb/s. Alas, this number did not prove out at all in real testing.
In fact, the best we were able to achieve is results right in the same range as using 802.11g. And depending on which channels we used (making sure not to conflict with any of the other routers in the house), we saw rates drop as low as 2 Mb/s. Sensing that something must be wrong, we called Linksys for help. Unfortunately, even after an hour with one of their 802.11n specialists, turning off all the other routers in the house, and even placing the laptop directly next to the router, we never got above 28 Mb/s. And the effective range of the unit was only slightly better than an 802.11g access point.
So what are we to make of this result? To be sure, the house in which the tests were conducted is a challenge under the best of times, as it is full of lead paint. But even when there was nothing between the router and adaptor but a few inches of air, the results were still poor. The Linksys representatives said that we weren't seeing typical behavior, and we're willing to give them the benefit of the doubt. Still, we have to report the results we actually got, and those results showed no real benefit over current 802.11g technology.
In fact, the WPC300N was significantly worse dealing with a congested Wi-Fi environment, as opposed to existing access points. It seems to really want to be the only dog in the yard. There's also the fact that you're going to be buying a product based on a standard that's still in draft form, and could change (perhaps significantly) between now and the final version.
Although the vendors are all saying that they're going to try to offer firmware upgrades to the final version, no one is putting that guarantee in writing.