Are you reading the reviews on pre-802.11n products? So am I and it’s not all good. I just completed a search for ‘802.11n reviews’ on Google and discovered some themes running through them.

Here’s what I found:

1. Many reviewers are advising not to buy any pre-11n device. They say to wait for products based on the fully ratified 11n standard, expected sometime in 2008.

2. There are continuing problems with interoperability between 11n devices from different manufacturers.

3. Interoperability between devices depends on whether they use the same chipset and firmware.

4. Draft 802.11n, v1.10 solves the backward compatibility problem with both good news and bad news.

Good News – backward interoperability with legacy 11b and 11g is required for standard compliance.
Bad News – when an 11n device detects a legacy network, it clocks back to less than half its speed.

5. 11n will not reliably stream high-definition video throughout a home. Highly compressed video for small-screen formats should not be a problem.

6. Like 11a/g, 11n drops speed rapidly with distance.

7. Despite the above limitations, 11n is definitely faster and reaches farther than 11a/g.

In many cases, 11n is being promoted and perceived as the solution for streaming media in the home because it is up to 5x faster than 11g. (Otherwise, why would you need the extra bandwidth?) As is being discovered, this is a half-truth.

Sure, 11n is very fast, much faster than 11g. That’s a fact. So, what’s the problem? Well, there are at least two.

First, the fantastic speed promised by 11n products, up to 5x that of 11g, is only realized within a short range. The speed offered by any Wi-Fi products diminishes very quickly with distance. However, two units from the same company that use advance smart-antenna beamforming techniques, mitigate this problem for short point-to-point applications.

Second, 11n devices will soon throttle back to less than half their potential performance when they detect the presence of an 11g device. That’s because the new 802.11n, v1.10 specification requires that 11n devices must change from the normal 40 MHz clock rate to 20 MHz when a ‘legacy’ network is detected. This is to ensure interoperability with legacy devices.

So, here’s the problem, you invest in an 11n network for your home and your neighbor has an 11g access point that throttles your network back to the 50 Mbps to 75 Mbps range, or even slower. (Those are the close-in performance figures.) How revolting.

So, what to do? Here is what the reviewers are suggesting:

1. Don’t buy pre-11n devices. Wait for products based on the fully ratified 11n standard.
2. If you don’t really need the extra speed and reach, don’t buy 11n.
3. If you buy 11n, buy devices from the same manufacturer.
4. Check for the existence of 11g networks nearby before you install a next-generation 11n network.
5. Don’t expect 11n to be the answer for streaming standard- and high-definition video throughout your home.

The bottom line: 11n does offer higher performance over greater range than 11g, even when throttled back in the presence of a legacy device. 11n does deliver better performance but it can’t be expected to deliver high-bandwidth coverage over the entire home.

The only thing that I can add is that there are exceptions to general rules. Each consumer will have to taste and see.

Stay connected!