As I finish up the third day of frustrating testing with the Netgear WNR 3500 Wireless-N Gigabit router, I’ve come to a simple realization: There just aren’t enough channels at 2.4 Ghz to make 300 Mbps wireless N work.

Wireless-G has 11 channels (conveniently numbered 1 thru 11). There does seem to be a bit of a bleed into adjacent channels, so if your neighbor has a router at channel 6, you may not be able to set yours to channel 5 or 7 and get reliable connections.

Wireless N gets to 300 Mbps by combining 4 adjacent channels into one big, fast 300 Mbps channel. So the channel options become more limited:
Channels 1 – 4, 2 – 5, 3 – 6, 4 to 7, 5 to 8, 6 to 10, and 7 to 11. So there are only 7 possible choices.

But where it gets difficult is if you have neighbors or interference in any of the 802.11 channels. If channel 3 is being used by a neighbor, then you only have 2 choices:
6-10 or 7-10.

If you have a neighbor on channel 3 and a neighbor on channel 7, then you don’t have any choices, aside from upgrading to dual-band wireless N, which will give you channels and 2.4Ghz and 5Ghz.

Netgear WNR 3500

This router is the main ingredient of the fastest wireless performance I have ever seen. A few weeks ago I wrote about getting 70 Mbps with the Trendnet TEW-624UB and this router.
What I wanted to know however, was how well this router does with other wireless adapters, and how fast. So I assembled the following assortment of wireless products and put the WNR 3500 through its paces:

1. Trendnet TEW-624UB Rev A (USB)
2. Linksys WUSB100 (USB)
3. Netgear WN511T (PC-CARD)
4. Linksys Wireless-G PCI (plain vanilla wireless G)
5. Trendnet TEW-624UB Rev B (USB)
6. Linksys WUSB600N (USB)

Let me make this quick and painless: There are 3 modes you can configure the WNR 3500 to: 300 Mbps, 144 Mbps, and 54 Mbps. If you want to get the claimed 300 Mbps you have to set it for that mode. If you do that, the ONLY adapter I could get this router to work consistently with is the Trendnet TEW.

Thats right, the only 2 adapters of the 6 I listed that work AT ALL in 300 Mbps mode are the Trendnet adapters.

The same was true in 144 Mbps mode. Only the trendnet adapters worked reliably enough to do any performance testing.

In plain old 54 Mbps mode, this product worked well with all of the test adapters. So there it is.

My theory: Too many varieties of Draft Standard N products are floating around.

The pathetic part is that even the Netgear WN511T, which is the recommended USB adapter on the back of the Netgear WNR 3500 box didnt work in 300 Mbps mode. Now it could be interference, but I would remove the other adapters, and plug in the Trendnet adapter, and every time it would work perfectly. So if it is some interference problem, the Trendnet is able to deal with it, and the other products can’t. So either way this is ugly for Netgear.

The one key thing to note, is that the WNR 3500 is 2.4 Ghz only. And that dovetails into another theory: 2.4 Ghz is ruined. It’s just too crowded with wireless phones, microwaves, baby monitors, your neighbors wireless routers, etc. 2.4 Ghz is a mess. In some places your lucky to get 54 Mbps working, and 54 Mbps only requires 1 channel. 300 Mbps requires 5 channels. So good luck with that.

I think if you want your own safe and uncrowded place for wireless networking, your going to have to get Dual-Band wireless N products. So even if this router is great, and the other non-Trendnet adapters are just shoddy, you really want a product that can go fast AND slow. Dual Band routers promise to do that, you can configure a 54 Mbps compatible 2.4 Ghz band (and only take up 1 channel), and then configure the 5 Ghz to be 300 Mbps. At least until all your neighbors upgrade to 5 Ghz.

Good luck and happy networking.

Trendnet TEW-632BRP

Today I noticed that Fry’s is selling the Trendnet TEW-624UB adapter for only $19 (Price is good until December 23rd) .  Last month I paid $59.  This cheaper model has the same exact UPC as the $59 version, but the hardware revision listed on the back is B1.1 instead of A1.0.  The new packaging doesn’t list its 802.11N as draft anymore. So this $19 adapter is the newest model version.

If you read the packaging carefully, you’ll notice it has 2 internal antennas, where the previous version had three.  I’m hopeful that performance or range isn’t reduced,  but I will be testing it shortly.

Closeup of Trendnet TEW-624UB Revision A Box Back

Closeup of Trendnet TEW-624 UB Revision B back box

So I had to try and find a new adapter to see if I could get reliable results.  So I found a new adapter to test with:  the  affordable Trendnet TEW-624UB.   The fastest I had previously seen the Trendnet TEW-624 go was 30 Mbps  (with the Netgear RangeMax Dual Band WNDR 3300).  The Trendnet USB connected right away to the WNR 3500. The first test I ran was Transmit, and it went really fast: 64 Mbps!  I didnt trust the results so I ran it again and got another 64 Mbps result. On the third transmit test run I got 71 Mbps! So thats the new record.

I also did receive testing, and got record breaking results: a solid 42 Mbps!  So there it is.  Congratulations to the new champs:   The Netgear WNR3500 RangeMax Wireless N Router and The Trendnet TEW-624UB USB adapter.

Oh..I don’t like the WNDA 3100 anymore because during transmit testing it dropped its connection, twice. After the second connection drop, I decided to flunk the product, its either gone bad or just flaky. Either way its not reliable.

Netgear WNDR 3300

I’m explaining my wireless testing in detail with this post so I can abbreviate more and hopefully make it quicker to write up product reviews later on.  After installing the wireless router and adapter, the main way I test is to do lots of file copies between my test machine and a file server directly attached to the wireless router. I copy the same amount of data each test pass,  so I just have to measure how long it takes,  and do some basic math to arrive at the effective throughput in millions of bits per second (Mbps).    

My server is a fairly standard Windows 2003 machine with striped SATA II hard drives. To keep things simple for performance testing, all machines are in the same room. I usually get an excellent connection.  I always enable encryption on the router, I’m not about to let my neighbors get access to my machines. I generally use the best encryption settings possible for the router/adapter pair I’m testing.  Nearly every product I test supports at least WPA-AES. 

I keep my house wireless router on channel 1,  so I have the most number of adjacent channels free to test on.  I set the router I’m testing to channel 6 or 11.

I sanity check the wireless routers by directly connecting test machines and server with the built in Ethernet ports and doing the same file copy testing.  With a 100Mbps Ethernet adapter in my test machine, I can consistently see ~90 Mbps.

I call file copies to the server “Transmit testing”, and copying files from the server “Receive testing”.  Sometimes I see big speed differences in receive and transmit testing and I’ll note this in my reviews when that happens. 

Surprisingly, I also see some adapters lockup or routers reset after doing as little as 200MB of file copies.  It’s easy to tell when your router is resetting if your in the same room because the Ethernet and Wireless connections will both drop for a minute. I don’t know how some products get shipped performing like that.

So I think that the way I’m testing is OK, I get good results, and more importantly my results are repeatable. 

I don’t do any special testing on wireless adapter drivers, yet.

Why is WLAN still so slow? How come wireless-N products don’t test significantly faster than plain old 802.11G?

I’ve been doing lots of performance testing of WLAN products and writing up the results on my blog (www.bohannontech.com). I was excited at first because I bought some nice new 802.11N 270Mbps products from all of the major brands, Linksys, Netgear, D-Link, and Trend. These products often show a connection speed of 270Mbps, but the actual speeds of file copies is terrible – some as slow as 6 Mbps, and this is with 2 computers in the same room. When I run the same tests with wired Ethernet, I will consistently get 80Mbps.

Has anyone been able to get a real performing wireless-N setup and if so, can you recommend any products?

These are the great responses I received, thanks again to everyone that helped out!

http://www.linkedin.com/answers/technology/wireless/TCH_WIR/373905-19281169

A NETGEAR WNR3500 in 300Mbps mode at Channel 6,10 and a NETGEAR WNDA 3100.

The windows connection speed on my test PC showed 300 Mbps, and I had to have my test machine in the same room as the WNR3500. 

The first test run was fairly fast, about 27 Mbps. The second test run was slower, about 25 Mbps, but during both of those tests I saw throughput spike to the high 30s, so I knew it could go faster if I got a “clean” run.

3rd time was a charm, I got clean test run that measured at 38 Mbps. Hey after a disappointing two weeks of product testing, that’s the fastest non-Ethernet connection I’ve seen.

It’s ironic that I got this result with the NETGEAR WNDA 3100,  after it had performed so poorly with another Netgear product, the WNDR 3300. I guess it works better with the WNR3500

One unusual twist: while testing the WNR3500 in 300 Mbps mode at channels 6,10 my home AP which I have set at channel 1 was completely unreachable. When I turned off the WNR3500 I could connect to my home AP again. I guess the WNR3500 is the king of the spectrum when its in 300Mbps mode.

Update 12/13/2008: I re-tested with this combination today, and I discovered that when I try to copy files to the server, the connection drops, and the adapter must be disabled/reenabled for it to connect to the network again. So I cannot recommend the WNDA 3100 anymore. Read my new post today to find the best setup so far.

So I’ve got a NETGEAR recommended solution here – two Wireless-N Products and they are literally sitting on top of each other. This should be the best case scenario for NETGEAR.

I couldnt even get it to connect with the default settings! 802.11N Channel 36 (5.180Ghz) must be a busy place. I must have tried 4 or 5 other 11N channels before I finally found out that I could connect on channel 157.

To someone not familar with this device (me!) it would be very difficult to get a 270MB connection out of the box. What I would do differently next time is make the SSID for 11G and 11N different, and then go about finding all the broken 1N channels in my house. Then I’d set the SSID’s to be the same and you’d be all set with a dual band AP. Good luck with that.

So connected at 11N, with my connection speed showing 270Mbps (looks impressive btw) my performance tests clock the connection at a measly 29Mbps. I ran the test a few times and got the exact same speed.

For completeness I configured the same PC to connect to the 11G SSID on the AP. The connection showed a perfect 54MB connection. I was really suprised to find out that my file copy test only got 9Mbps! The file copy test ran faster 2 floors apart than 2 inches apart.
I noticed that the NETGEAR packages have stopped making any speed promises. That’s probably a good idea when two 802.11N products 2 inches apart can’t get anywhere near 100MB Ethernet speed.