Taking the Leap into 802.11n
Apple recently announced its new AirPort Extreme 802.11n wireless base station.
We help you navigate the wild and wooly world of pre-standard wireless network gear.
It sounds too good to be true. 802.11n, the next-generation wireless network standard, delivers 100 Mbps or more throughput (true speed, not data rate) with more than twice the range of current 802.11g/a wireless network products.
So what’s the catch? No standards, no certified products, limited interoperability, and no guaranteed firmware upgradeability.
The 802.11n standard probably won’t be ratified until the fall of 2008, but vendors began releasing “pre-N” and “MIMO-based” products based on initial iterations of the specification more than two years ago. So today you’ll find products based on draft 1.0 of the spec alongside standards-based g/b/a equipment from vendors such as Linksys, Netgear, Buffalo Technology and D-Link.
The 802.11n standard is built primarily using a complex technology called spatial multiplexing, which uses a concept called MIMO (which standards for multiple-input multiple-output). MIMO typically uses two or three antennas to receive (input) the signal and two or three radios to transmit (output) it, plus special signal processing to improve range and throughput.
Unlike the b/g/a wireless products, this next-generation nonstandard equipment hasn’t been certified to interoperate with other vendors’ gear, nor is it guaranteed to be firmware upgradeable to future versions of the spec.
Now for the good news. If you’re looking to buy pre-N products now, products based on version 2.0 of the 802.11n draft spec are just a couple of months away.
Aside from being closer to the final spec architecturally, the 2.0 draft spec rectifies some problems with “channel bonding,” a function that could cause your network to knock down the speed of your neighbor’s.
Also, most vendors are claiming their version 1.0 products will be firmware upgradeable to version 2.0. That’s very good news for early adopters and people buying 1.0 draft products today. Vendors that guarantee firmware upgrades could gain a competitive advantage.
Better, the IEEE Wi-Fi Alliance—the industry group charged with finalizing the spec and conducting interoperability testing—plans to begin interoperability testing draft 2.0 products in late spring. So the version 2.0 products you buy soon might actually work across vendors.
The Wi-Fi Alliance doesn’t encourage the purchase of nonstandard products. But in the case of pre-N, it’s had to bend to vendor pressure and is now creating a certification program for draft 2 “pre-N” products. Certified products will be guaranteed to interoperate across vendors.
Even so, to be on the safe side, we recommend you buy all your “pre-N” gear (regardless of version) from the same vendor, sticking to the same product line containing the same chipsets. Homogeneity all the way.
Where you could run into problems is if you by a new laptop computer with embedded “pre-N” network cards—they’re Intel Centrino based chips, not the Broadcom, Airgo or Atheros chips you’ll find in your adapters, access points and routers, for the most part. If such a laptop gives you trouble, disable the network card and buy one that matches the rest of your gear.
Just keep in mind: Given wireless technology’s finicky nature, there’s no way to know how well any of these products will work until you set them up in your home. The actual throughput of wireless devices depends on physical surroundings such as room layout, the thickness of walls, placement of microwave ovens and refrigerators, windows, and so on. (See “Test Your Network Speed,” below)
So if you can wait, wait at least for the draft 2.0 products. But if you’re living with an 802.11g network with spotty coverage, or you can’t get a signal up to your attic or out to your detached garage—and you have the bucks to experiment—go ahead and buy. Just keep your receipts handy, because with pre-N, nothing’s guaranteed.
Test Your Network Speed
If you’re investing a few hundred dollars on a “pre-N” network, download a network performance analyzer to see if you’re getting your money’s worth. If you’re not getting the promised range or throughput, you can always box it
Unispeed NetLogger Workbench 3 ($199; 15-day free trial)
Ipswitch What’s Up Gold ($2,595; 30-day free trial)
Pre-N Products Currently Available
Here’s a handy list of key product information for the most popular “pre-N” products. Chipsets can vary by vendor product line (Airgo, Broadcom, Atheros, Intel), so if you can’t tell from the product literature, ask before you buy. Note, a slew of new laptop computers (i.e., Toshiba, Acer, Apple, others) are coming out with Intel’s Centrino “pre-N” chip.
- WL-566gM router, WL106gM adapter
- WL-566gM router, WL106gM adapter
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