Making the Choice
If you have assessed your bandwidth and throughput needs and understand the concept of bandwidth vs. distance, you're now ready to start choosing your wireless LAN gear.
I have spent years testing all manner of consumer wireless LAN products. So believe me when I say that your choice of the technololgy used in wireless LAN products rather than the brand will be the main determining factor in the maximum throughput and bandwidth that you get. Table 3 is just another way of looking at the data presented in Figure 2.
|Product Technology||Approximate Maximum
|20 MHz B/W||40 MHz B/W|
|Draft 11n - 1T||40||60|
|Draft 11n - 2T||60||80|
|Draft 11n - 3T||70||90-100|
Table 3: WLAN Technologies vs. Maximum Throughput
You can mix and match any manufacturer's wireless routers, access points and clients for 802.11b and 802.11g because they are finalized standards. But once you get to the other technology flavors, you need to match flavors to achieve the performance you see in the table.
For example, products based on Atheros' proprietary "Super-G" technology use channel bonding to achieve the higher bandwidth that you see in the 40 MHz B/W column. (The same technique (with a different implementation) is used in draft 11n products.) So you need Super-G technology in both AP and client in order to achieve the higher bandwidth. (Super-G products can generally be identified by the use of "108 Mbps" somewhere in the product spec.) Note that you can still mix Super-G and standard 802.11g products, but you will at best achieve only 802.11g speeds.
Draft 11n chipset manufacturers have greatly improved interoperability. But since each is still tweaking performance algorithms, your best bet at achieving maximum throughput will come from using the "matching" adapter for a given router. Manufacturers generally name the router and adapters similarly to "help" you with this, i.e. RangeMax Dual Band, Ultra Range Plus, etc. Note that this won't guarantee maximum performance, but it will give you the best shot at it.
If you're into performance details, our Wireless Performance Charts have throughput vs. path loss curves for many products and let you compare multiple products. More recent products use a six location open air test method that we have returned to using since we had to return the ACE system to Azimuth. The open air method uses a real-world residential test environment that is as controlled as we can make it.
Remember that the results from both test types can be used only to compare relative product performance. Performance in your home or office will probably be different.
Most of consumer wireless "base stations" come in the form of wireless routers, not access points. Fortunately, the routing features of most consumer routers are more alike then different and most are fast enough to keep up with even fiber-based connections. But check the throughput using the data in our Router Charts if you have a fast connection, just to be sure.
If you have special routing needs, or aren't sure if you do, then you should perform an assessment of your routing needs. Fortunately, we have this article to help you through that process.
If you already have a router that you like, but want to upgrade your wireless, you can convert any router into an access point by following the few simple steps described here. But you won't even have to do that if you select one of the wireless AP/bridges or upgrade kits that are being produced with draft 11n upgrades in mind.
Even with all this homework done, there are a few other points to consider before you click that Buy button.
- Don't rush to buy a draft 11n router, especially if you have an investment in 802.11b/g devices and adapters. Unless you're upgrading from a very old 802.11b router, you won't see a significant improvement in range from draft 11n.
- Don't buy a draft 11n router and then run a mix of draft 11n and 802.11b/g clients. The current crop of Draft 2.0 routers provide reduced performance for both 802.11n and b/g clients when running a mixed network. See this article for more details.
Keep your existing 11g router (or buy a new one) for your 11b/g clients and run a separate draft 11n router for those clients. Just decide which one you'll use as your main router and convert the other to an access point, using the article referenced above.
- Don't buy "faster" wireless to speed up Internet-based applications unless your Internet connection can handle it. A big wireless "pipe", connected to a little Internet "pipe" won't do you any good for Internet use. It should, however, help speed local (LAN/WLAN) traffic.
- Dual-band vs. single band. I'm no longer recommending that you go for dual-band dual-radio products if you want to move now to draft 11n. The main reason is that the potential upside isn't enough to justify the high cost, especially if you have a large installed base of 802.11b/g devices. This article has the full story.
The main reason to buy dual-band products is to access the relatively interference-free 5 GHz band. But the downside is that you'll have reduced range, especially if you try to use the 40 MHz channel mode that some 5 GHz products default to. Unless you really need the higher bandwidth or speed and have modest range needs, I recommend setting the 5 GHz radio to 20 MHz channel mode to stretch your WLAN's reach a bit farther.
I know that this is a lot of homework to do and even when you're done the answers aren't crystal clear. But as I said at the beginning, the most important factor in being satisfied with your choice of wireless LAN gear is having your expectations set properly.
If you expect miracles, I can pretty much guarantee that you won't be happy with any WLAN product. But if you understand the nature of the beast and your needs are modest, then you're on your way to being a happy wireless LAN camper.