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Draft 802.11n Revealed: Part 1 - The Real Story on Throughput vs. Range

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June 1, 2006 3:31:01 PM

Don't read this article if you've already made up your mind to not buy draft 802.11n products. But if you're still optimistic, Tim Higgins offers an unprecedented look at how some draft 11n products don't even beat 11g!

More about : draft 802 11n revealed part real story throughput range

June 1, 2006 4:49:22 PM

Why do the test if you are not going to do it right?
June 1, 2006 7:29:33 PM

And the definition of "right" is?
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June 1, 2006 7:37:53 PM

Regardless of the results posted, if you live in a crowded Wi-Fi area like myself (townhouse community) forget about hi-speed wireless connections. I have owned 3 different Netgear Super-G routers and that Netgear 240, none run as fast as regular G. My guess is that they force you to Channel 6 where there is tremendous interference and limited bandwidth left. I finally gave up and just changed my router configuration to channel 10 with standard 54Mbps G and my performance increased by 2-4 fold depending on the moment! Channel 10 just happened to work for me. It sucks b/c I'm constantly moving large files from different computers in my house and the only real alternative is wiring the house which isn't a fun looking chore. So anyone looking to buy a product faster than "G" for speed sake, you might want to relocate to one of the poles if you hope it will work as advertised.

Just in case you were wondering I have about 16-18 wireless networks showing up at any one time (those are just the ones broadcasting). And moving a Gigabyte sized file regardless of distance utilizes about 3-6% of the network connection when using XP's task manager to look at network utilization with Super-G or 108 Mbps configured. Which I'm aware only hits about 40-50 % with a wired connection at max.

Well that is my input.
June 1, 2006 8:29:21 PM

Have you tried using 802.11a?
June 1, 2006 10:35:29 PM

We went through this with 11g. Why would expect anything different.

Besides they have had over 3 yrs now, and they still havn't got the drivers worked out for 11g. What did they do to fix it. They sent their support to India and who knows else where. This way they are isolated from what is really happening. And they wonder why they have PR problems.
June 1, 2006 10:44:21 PM

Nice review, thinking outside of the box. I hope you ADD this information to all future reviews.

I'm glad your conclusion touched on the MIMO multipath issue, otherwise I would have been pretty disappointed. I would have to guess that multipath issues are larger at the longer ranges. MIMO may still have a large advantage at range. (fingers crossed)

In terms of is this the 'right' way of testing hardware, it is hard to say. I personally liked the old way, with several locations. It was good for real world comparisions. I think the method presented is good for testing only part of a product, the radio. The antenna that comes with a 'product' may make or break it's performance; look at all the DIY and aftermarket antennas available.

Keep up the good work!
June 2, 2006 7:09:09 AM

What about Belkin? I remember reading somewhere online that Belkin was the pre n leader right now in terms of highest speed over greatest distance.
June 2, 2006 7:55:07 AM

Quote:
And the definition of "right" is?


Tim,

Awesome job on the testing. A fairly important factor that you missed, however, is the difference in the transmit powers of the units. Airgo has done a great job at confusing the pundits by using very high power PAs (power amplifiers). Airgo's FCC-reported power is 25dBm, while Marvell is at 17dBm. 8dB is approximately 6x the power. Additionally, Marvell's Netgear design does not use low noise amplifiers (LNAs). These help with reciever sensitivity and will add several more dB of confusion to the mix. All this is important since folks are comparing 802.11 silicon vendors themselves more so then full designs. BTW, all this info is readily available on the FCC website.

If you are comparing silicon, then you need to correct for the difference. From your plots it looks like the performance delta is around 15-18dB in favor of Airgo, however 8-12dB of that is due to PAs and LNAs; someone else's IP. Obviously the same parts are also available to Broadcom/Linksys, Marvell/Netgear, etc.
My takeaway is -- Airgo's gen3 chips are 3-6dB better then Marvell's/Broadcom's gen1 chips. Let's not forget that Airgo has had several more years tuning their driver. My hunch is that Marvell/Broadcom is leaving more than 3-6dB on the table with their not yet mature drivers.

Thanks for the wonderful comparison.

The_tooth.
June 2, 2006 11:31:07 AM

Wow, I'm worried about the Cisco results 8O

How comes that they are THIS bad?

What drivers and IOS did you run on the AP and STA?

Thanks,
pato
June 2, 2006 12:12:26 PM

Quote:
What about Belkin? I remember reading somewhere online that Belkin was the pre n leader right now in terms of highest speed over greatest distance.


The limited time that I had with the Azimuth system didn't allow me to test more products. The Belkin "Pre-N" products use Airgo's first-generation chipset, which doesn't use channel bonded 40MHz bandwidth.
June 2, 2006 12:15:12 PM

Quote:
What drivers and IOS did you run on the AP and STA?


*Cisco AP:*
Series 1200
Model: Air-1232AG-A-K9
Software: 12.3(7)JA
Bootloader: 12.3(2)JA3

*Cisco Client:*
Aironet 802.11/a/b/g
Model : AIR-CB21AG-A-K9
Driver: 2.1.0.2 (may 11, 2005)
June 2, 2006 2:14:38 PM

Quote:
Awesome job on the testing. A fairly important factor that you missed, however, is the difference in the transmit powers of the units.


Thanks and point taken. You're correct that the power and LNA used in the end-products can significantly affect results. As well as antennas, firmware rev, manufacturing qualilty, board layout, etc.

I use the terms "Broadcom-based", "Marvell-based" as I have in the past, as a matter of convenience and to indicate the primary source of the product design. My test methods aren't detailed enough to separate out the specific sources of the component contributions to total throughput.
June 2, 2006 3:18:07 PM

Great job on putting together the test and article! In my line of work, I get to play with different flavors of routers. I recently took home the Netgear RangeMax 240. This article pretty much concurs with my own experience with this router. I live in NYC and there is about 10 wireless networks around my apartment (I live on the second floor of a two family house). I was delighted to find out that I can stream an MPEG4 video at 8Mbps into my laptop. I was using a Netgear WPN511 PC Card in the laptop. I could never get pass 2.2 Mbps using another Netgear Router (WGT634U). I also did some simple benchmarks using share copies (SMB). This test showed around 80 Mbps total throughput. The only negative that I can say about the RangeMax 240 is its lack of a real firewall.

BTW, a great piece of free software that I've used in the past to perform throughput testing is <a href="http://analyzer.polito.it/download.htm">Analyzer</a>. It has a real-time graph of network throughput. I'm curious on how much the Azimuth setup cost.
June 2, 2006 3:39:46 PM

Quote:
Great job on putting together the test and article! In my line of work, I get to play with different flavors of routers. I recently took home the Netgear RangeMax 240.


Glad you enjoyed the article. I suspect part of the reason that you were getting such good results with the RM240 is that it is stomping on any of your neighbors who are on Ch6!
June 2, 2006 3:44:36 PM

I looked at a dual-band router but they are sorta hard to come by and I was a bit discouraged by the price of changing out my wireless cards and router. I made the mistake of investing in 4 wireless cards and a router before realizing the problem of network interference. I figured I'd just suck it up and wait till they come up with something that works as advertised....but 11n is a fading hope.
June 2, 2006 3:47:27 PM

Yes, I suspect that is probably what was happening...as a good neighbor I decided not to keep the router :D .
June 2, 2006 3:52:17 PM

In my original Netgear Router firmware they had a mode called forced super-G or something to the effect. That worked really well compared to the replacement mode of auto-108. I was forced to upgrade my firmware when I purchsed my Xbox360 or my Slingbox, I can't remember which and lost the force mode in the process. Any ideas what the force mode did that made the performance so much better than the auto mode? Basically if I ftp'ed a file in the force mode I could obtain near line speed connections but in auto well...just plain sucks and I get better performance with plain G using a different channel. Why did they drop it in the later firmware revisions?
June 2, 2006 3:59:46 PM

You're a better neighbor than me. ha ha...I had dismal results with that router using rangeMax and super-G cards. Had it of worked I would of kept it. But I could never get more than 1MB/sec downloads over wireless which was worse than what I was getting with my plain super-G setup at the time. At the time of my purchase the cards specific to that router were not on the shelves yet, so that could of possibly of yielded better results but they were also in the neighborhood of $100 per card at the time and I wasn't interested in changing all my wireless cards on a chance.
June 2, 2006 4:05:05 PM

It was very tempting to keep. My connection didn't get any better when I used it with my 108Mbps cards either. I was hoping it would. The throughput I was getting was when I used it with the Netgear RangeMax card. Strangely enough, when I used my laptop at close proximity of this router (about 3-5') I would lost signal.
June 2, 2006 4:12:27 PM

Quote:
I looked at a dual-band router but they are sorta hard to come by and I was a bit discouraged by the price of changing out my wireless cards and router. I made the mistake of investing in 4 wireless cards and a router before realizing the problem of network interference.


You're right that there aren't many dual-band products. Networking manfs say this is because buyers only want 11g. But I tell them that the reason is that they (the manfs) have trained consumers to ask for 11g with all the hype about speed.

In the end, if you have a crowded spectrum, the only way to get reliable wireless connection and speed is to move to a band that is less crowded. Believe me, at some point soon, the manfs will start talking about dual-band again.
June 2, 2006 4:21:00 PM

I was surprised that they didn't move to a higher band like the "A" with the new 11n standard, but I guess that might of caused some problems with backwards compatibility without making every thing dual-band in essence to support the legacy equipment. Also I remember a little bit from communication class that the higher the frequency the less range, but couldn't that just be solved with more amplification? Why is everyone sticking to the 2.4GHz spectrum and that channel 6? Is it because the chips and technology are so readily available that it keeps cost down?
June 2, 2006 7:03:14 PM

For the Netgear RangeMax Next throughput results, you stated that they achieved 102Mbps in the article but your Chariot graph showed 100.2 Mbps...
June 3, 2006 5:09:12 PM

Kudos to the realisation that wireless comparisons are almost always flawed.

Good job, but look forwart to the multi channel testing. Will be an interesting read.
June 3, 2006 5:24:22 PM

Tom, I applaud your efforts to test this gear but there are a few things I'd like to point out.

One thing is I wish reviewers like yourself would get all over these irresponsible companies for laughably calling these products "draft 802.11n". Firstly, there is no 802.11n draft in IEEE yet, so how can these be compliant to a an IEEE draft that doesn't exist yet? The IEEE 11n task group had narrowed things down from multiple to one draft proposal, but the membership of the task group has NOT passed a vote yet to adopt that proposal to be the first draft of the 802.11n standard. There is no draft yet, so how can these products claim to be compliant to a nonexistent draft? Folks in the techology press corps should be asking these retailers about this.

Second they're not even compliant to the proposal so they shouldn't be allowed to put 802.11n at all on their boxes. The 802.11n draft proposal calls for 802.11n to operate in BOTH the 2.4GHz and 5GHz frequency bands. These devices only operate in the 2.4GHz band so there's no way they are ever going to be compliant with any draft of the 802.11n specification at all! The best branding that these products might be able to claim is something like MIMO 802.11g, they resemble nothing which will be able to rightfully call itself a true 802.11n product because they are single frequency products only.

Now regarding your test methodology, I'm sorry to say it is flawed and won't produce accurate results which would mirror the results you would see in the real world. I applaud you for trying to use a reproducible test methodology in your use of the Azimuth system, but you really should have been using the Azimuth MIMO Functional Test solution http://www.azimuthsystems.com/index.asp?p=250 to do your tests rather than what looks to me to be just the basic Azimuth system. A single path near field test is not really giving an accurate waterfall plot of a MIMO system because MIMO systems rely on multipath to provide some of their range advantage in the real world. I would really like to see you talk to Azimuth to get their MIMO test solution and repeat your tests and post the results here as I think the results would be quite interesting.

Thanks for posting this review though, I found it very interesting and I hope you do more of these with the Azimuth MIMO test fixture in the future.
June 6, 2006 12:53:34 PM

Quote:
For the Netgear RangeMax Next throughput results, you stated that they achieved 102Mbps in the article but your Chariot graph showed 100.2 Mbps...


Sorry, and thanks for catching it. Corrected.
June 6, 2006 12:56:22 PM

Quote:
I was surprised that they didn't move to a higher band like the "A" with the new 11n standard, but I guess that might of caused some problems with backwards compatibility without making every thing dual-band in essence to support the legacy equipment. Also I remember a little bit from communication class that the higher the frequency the less range, but couldn't that just be solved with more amplification? Why is everyone sticking to the 2.4GHz spectrum and that channel 6? Is it because the chips and technology are so readily available that it keeps cost down?

I'm also surprised that manufacturers aren't introducing dual-band 11n products. Since prices for the new products are high anyway, the incremental cost of dual-band wouldn't be noticed as much.

The range problems with 11a products were fixed by Atheros in its 2nd generation gear.

I don't get the obsession with 11g either...
June 6, 2006 1:17:05 PM

Quote:
One thing is I wish reviewers like yourself would get all over these irresponsible companies for laughably calling these products "draft 802.11n". Firstly, there is no 802.11n draft in IEEE yet, so how can these be compliant to a an IEEE draft that doesn't exist yet?

There is a 802.11n Draft 1.0
http://grouper.ieee.org/groups/802/11/Reports/tgn_updat...
It recently failed the vote to accept it as the standard.

Quote:
Second they're not even compliant to the proposal so they shouldn't be allowed to put 802.11n at all on their boxes. The 802.11n draft proposal calls for 802.11n to operate in BOTH the 2.4GHz and 5GHz frequency bands.

It is my understanding that 802.11n does not specify a band of operation. Its speed-enhancement technology can be applied to either 2.4 or 5GHz equipment.

Quote:
Now regarding your test methodology, I'm sorry to say it is flawed and won't produce accurate results which would mirror the results you would see in the real world.

I did consult with Azimuth for this article since they arranged use of the system. I have also asked Azimuth for its formal comment on this issue. Informally, they have told me that open-air tests with multipath effects would not produce higher speed, but would allow operation with lower path loss (distance).

In the meantime, both Broadcom and Atheros have gone on record endorsing the Azimuth system for MIMO testing in the configuration that I used. http://www.azimuthsystems.com/index.asp?p=250
June 7, 2006 1:02:36 AM

HEY THIGGINS

A new WRT300N firmware was released today v93.3 - although it is dated June 1st...

Any chance of new results for the wrt300n since the firmware apparantly fixes wireless performance etc?

thanks for the review - i have a wrt300n on order as they are arriving in canada this week or next!
June 7, 2006 1:07:21 PM

Quote:
Any chance of new results for the wrt300n since the firmware apparantly fixes wireless performance etc?

I will be retesting at some point, but not anytime soon.
June 7, 2006 4:03:25 PM

hi Tim,

thanks for a great review of 11n stuff, and for acknowledging the limitations of the test medothology.

however credit where credit is due, this is probably one of the most environment-controlled tests on 11n stuff that's been conducted to date, and clearly reveals that fundamentals in vendor pre11n implementations are still far from complete.

your test is a comparative benchmark as to how far we're yet to go before 11n is worth most people's time and money, that can no longer be ignored by the manufacturers on the grounds of "well maybe your tests were subject to <insert their favourite peformance inhibitor disclaimer>.

your review exemplifies the reason why THG is as well regarded as it is - well researched and conducted tests, well written reports, open acknowledgement of limitations, and telling it like it is without sign of vested interest. keep up the good work.

Anthony.
June 7, 2006 4:40:18 PM

Quote:
your test is a comparative benchmark as to how far we're yet to go before 11n is worth most people's time and money, that can no longer be ignored by the manufacturers on the grounds of "well maybe your tests were subject to <insert their favourite peformance inhibitor disclaimer>.

Thanks for the kind words, and for understanding what the test was trying to accomplish.

I expected FUD to be generated regarding the test technique, which is why I didn't say it was "truth". The Azimuth MIMO test system obviously has merit and is being used by at least some (and I wouldn't be surprised if it were all) of the draft 11n chipmakers to develop their products.
June 7, 2006 5:31:21 PM

Tim, I'm not trying to generate FUD but the setup you photographed didn't look like the Azimuth MIMO Test Engine, it looked like their older product. So again, I would encourage you to go back to Azimuth and verify with them that what you tested with was their MIMO Test Engine.
June 7, 2006 9:10:51 PM

Quote:
Tim, I'm not trying to generate FUD but the setup you photographed didn't look like the Azimuth MIMO Test Engine, it looked like their older product. So again, I would encourage you to go back to Azimuth and verify with them that what you tested with was their MIMO Test Engine.

I tested with what Azimuth recently announced as its "MIMO Functional Test solution"
http://www.azimuthsystems.com/index.asp?p=250

I didn't use the "ACE Channel Emulator" if that is what you are referring to.
June 7, 2006 9:39:38 PM

That's what I'd love to see, is how this stuff works when tested with the ACE versus the tests that you've already done. I'd just like to know what variability in results you get in using the two different Azimuth setups.
June 8, 2006 12:12:34 AM

Tom,

So you are recommending a "don't buy" for the Airgo based products simply because they don't share the bandwidth well in 20/40MHz. I have two points:

1) In MOST environements, you don't have enough co-channel interference to dictate even caring about fair channel useage. Joe Blow in the suburbs is not going to have a problem if his neighbor is on an overlapping channel nor will his neighbor. Only in dense urban environments will this be a problem.
2) You overlook the fact that if you fix the channelization to 20MHz the Airgo based products still outperform anything on the market by a wide margin. So, if you have neighbors on a channel and you feel like being a nice guy, fix your AP to the 20MHz and still download stuff at 80Mbps.

My 2 cents. Nice job on the review. Definitely the most technical review available.
June 8, 2006 12:00:14 PM

I see the problem with your tests: Figure 10 clearly shows a GREY and red ethernet cable. You stated you measured a GREEN and red cable......
:) 
June 8, 2006 12:42:43 PM

Quote:
1) In MOST environements, you don't have enough co-channel interference to dictate even caring about fair channel useage. Joe Blow in the suburbs is not going to have a problem if his neighbor is on an overlapping channel nor will his neighbor. Only in dense urban environments will this be a problem.

That's the key question, do "most" environments have neighboring wireless LANs or not? It's not just urban environments that have housing density. Drive around suburbs in California, Nevada, or even my area near Charlottesville Virginia and there are plenty of 2,000 sq ft homes on 2500 sq foot lots - plenty close to be a problem.

Quote:
2) You overlook the fact that if you fix the channelization to 20MHz the Airgo based products still outperform anything on the market by a wide margin. So, if you have neighbors on a channel and you feel like being a nice guy, fix your AP to the 20MHz and still download stuff at 80Mbps.

Point taken. But since many ("most"?) users just take these things out of the box and set 'em up, I can't recommend a product/technology that isn't designed well enough to not interfere with a very large installed base of products that have enough problems sharing an overcrowded frequency space.
June 9, 2006 1:37:33 AM

Hey now, I may be off on the sidelines but I'm involved with 802.11T and haven't given up the ship yet! Granted some of the task groups do take a seemingly unexplainable length of time. 802.11T will also (the plan anyways) to have recommended tests and methodologies for video streaming and quality assessment. I do despise some of these vendors advertizing their products as HD quality over wireless. Sure, maybe in a RF chamber.
June 9, 2006 2:51:45 PM

Quote:
Hey now, I may be off on the sidelines but I'm involved with 802.11T and haven't given up the ship yet! Granted some of the task groups do take a seemingly unexplainable length of time. 802.11T will also (the plan anyways) to have recommended tests and methodologies for video streaming and quality assessment.

Sorry, zman. Didn't mean to dis you and the work that's being done.

Quote:
I do despise some of these vendors advertizing their products as HD quality over wireless. Sure, maybe in a RF chamber.

As do I. My position with all of them is that I haven't seen a product yet that can deliver a dependable video stream in a high-interference environment. 2.4GHz is too crowded for many (most?) users. 5GHz will be at least a temporary way to go until it, too, gets overcrowded.
June 10, 2006 10:17:44 PM

Quote:
Tom,

So you are recommending a "don't buy" for the Airgo based products simply because they don't share the bandwidth well in 20/40MHz. I have two points:

1) In MOST environements, you don't have enough co-channel interference to dictate even caring about fair channel useage. Joe Blow in the suburbs is not going to have a problem if his neighbor is on an overlapping channel nor will his neighbor. Only in dense urban environments will this be a problem.
2) You overlook the fact that if you fix the channelization to 20MHz the Airgo based products still outperform anything on the market by a wide margin. So, if you have neighbors on a channel and you feel like being a nice guy, fix your AP to the 20MHz and still download stuff at 80Mbps.

My 2 cents. Nice job on the review. Definitely the most technical review available.



Finally a reasonable easily understood post!

The testing was very laborously conducted and superb. However, as a reader looking for which router to buy, there was no "bottom line". To finish the article by saying that pre-n routers are not there yet and that no device is recommended is simply not helpful!

I think may readers of this article are looking for which router will work to give them the best speed and range for 802.11g devices (like every notebook out there these days). Spending so much time on the article discussing how running 802.11n and 802.11g mixed environment produces conflict is simply not helpful to the consumer from a buying perspective.

Personally, I am looking for which device to buy in a large suburban home where 802.11n is impossible, (since many of the clients have to have mini PCI cards installed which are only available in 802.11g.) Therefore, I am looking for how to get the best signal and range in the house. Should one go with multiple bridged conventional 802.11g routers vs. one powerful MIMO 802.11g?

It looks like the Netgear Rangemax 240 is probably the best choice out there right now. Yes, its an imperfect world, but it looks to be the best choice out there for conventional 802.11g range and speed.

Anyone have any thoughts about this vs using multiple 802.11g routers in bridge mode? A third alternative would be range extending using powerline such as the netgear wall plug ethernet bridge.

Maybe an article focussed on this comparison would be more helpful to the reader...

Again, a very informative read about problems with the emerging 802.11n.
June 11, 2006 3:18:20 PM

Quote:
The testing was very laborously conducted and superb. However, as a reader looking for which router to buy, there was no "bottom line". To finish the article by saying that pre-n routers are not there yet and that no device is recommended is simply not helpful!
Since the article was specifically about draft 802.11n products,

I think may readers of this article are looking for which router will work to give them the best speed and range for 802.11g devices (like every notebook out there these days). Spending so much time on the article discussing how running 802.11n and 802.11g mixed environment produces conflict is simply not helpful to the consumer from a buying perspective.

The article was not intended as a guide to the best wireless router. But since you asked...

If you have many neighboring 802.11b/g WLANs, there is 2.4GHz product that will give you reliable operation. You'll need to move to 802.11a products.

The best speed/range characteristics right now for 11b/g products are those using Airgo's first or 2nd generation chipsets. See this article for specific recommendations and test results:
http://www.tomsnetworking.com/2005/11/28/mimo_face/
June 14, 2006 7:52:32 PM

Tim,

Let me first give you the generous praise that's your due. You were the first. You're still the best. Your reviews combine experience with at least the breath of scientific method. Best of all, you're not afraid to slog, to grind, to go bleary-eyed with the detail and checking that make a review really useful. Heck, your charts even match your text data, most of the time (g).

Now let me explain why this particular review is useless to me. It may also tell you something about your future. I hope not, but....

I live in Manhattan, many floors up. Out one apartment window, I can "see" 14 networks. Out of another, I can see 11, only 3 of which are common with the first.

There's no sheetrock here. A WRT54G cranked up to 80-100 goes through ONE wall. It's even reliable transmission, if you use 5 dB antennas. Until summer. Then the humidity goes up, and the asbestos brick, common brick, wetwall plaster, plus the mesh lath that's in the walls become even better shielding than in the winter. Byebye wifi.

11a doesn't go through one wall. 5GHz; sorry 'bout that. We treasure our 900MHz phones - they work.

We drill. With 18" carbide bits. The walls are thick. We run CAT5/6. We keep our radios off, until we have an outage. THEN wireless is really handy, to avoid fallback to dialup. Yes, even in NYC you can usually find an open network nearby. In fact, I know of nearby buildings where they exchange keys!

Thought you'd like to hear about what happens in the end game of the Tragedy of the Commons.

-Frank, in CrowdedVille
September 18, 2006 1:35:34 AM

Quote:

The article was not intended as a guide to the best wireless router. But since you asked...

If you have many neighboring 802.11b/g WLANs, there is 2.4GHz product that will give you reliable operation. You'll need to move to 802.11a products.

The best speed/range characteristics right now for 11b/g products are those using Airgo's first or 2nd generation chipsets. See this article for specific recommendations and test results:
http://www.tomsnetworking.com/2005/11/28/mimo_face/


I am also looking for a new router that will give me the best performance with my existing 802.11g adapters. Would you still stick to the recommendations from the "MIMO Face-Off" article, or do you have some new recommendations for this situation?

Also, what performance enhancement am I gaining by using my existing 11g adapters with a Super-G/MIMO/Pre-N router over an 11g router? I have read the "Draft 802.11n Revealed" articles, but its still kind of fuzzy to me.

Thanks!
September 18, 2006 7:45:53 PM

Quote:
I am also looking for a new router that will give me the best performance with my existing 802.11g adapters. Would you still stick to the recommendations from the "MIMO Face-Off" article, or do you have some new recommendations for this situation?

Also, what performance enhancement am I gaining by using my existing 11g adapters with a Super-G/MIMO/Pre-N router over an 11g router? I have read the "Draft 802.11n Revealed" articles, but its still kind of fuzzy to me.

Thanks!

Yes, Airgo products are still your best bet if you want to try MIMO technology.

You *might* get some range improvement due to a more sensitive radio in the MIMO router. But your speeds will stay at 11g rates.
September 28, 2006 9:28:09 AM

For video applications , its is not the max. througput during TCP traffic that is important, but the packet loss at a certain througput of UDP traffic.

I never see results of packet loss tests.

Some manufactures are able to enhance the WiFi performance on UDP traffic. It would be interesting to see how the pre-N products compare to b/g products on packet loss.
September 28, 2006 4:15:28 PM

Quote:
For video applications , its is not the max. througput during TCP traffic that is important, but the packet loss at a certain througput of UDP traffic.

I never see results of packet loss tests.

Some manufactures are able to enhance the WiFi performance on UDP traffic. It would be interesting to see how the pre-N products compare to b/g products on packet loss.

You're right that it's UDP that is more important for streaming applications. Unfortunately, short of using a product like Apposite's Linktropy 4500 WAN Emulator, there is no easy way to inject controlled amounts of packet loss.

My experience in my Video Streaming article
http://www.tomsnetworking.com/2006/08/04/video_streamin...
was that it was harder than I thought to get packet loss under real-world conditions. Turns out that 802.11 technology is pretty good at not losing packets!

In the end, it was throughput that mattered the most.
!