But *8*? NFW.
Allot of people have written that they are interested in six -- it isn't much difference for us to make an eight port.
I'm sure most of these think they can run a six-sided sector setup. The self-interference will be huge.
With this argument, then only one radio should be allowed on each tower. Sorry to inform you, but most people have successful installations with more than one radio per tower. Have you ever been a WISP?
No, and I refuse to become one. :-) There will always be more capacity in a wire than in wireless. Wireless applications really need a 'mobility' component to provide the justification for the "expense" of the radios.
Many (many) people will try though. Things work, in general at low usage levels, and when the SIR is high.
And, btw, while I'm on this subject, 802.11 has fairly bad properties for WISPs, but its cheap, so they use it.
We (like you) do sell a lot of gear to WISPS, btw.
I've had a number of requests for a dual-card (and more) design. Typically I just explain the issues to the potential customer, and the light bulb goes on for them.
I designed two products for Vivato:
1) the new 'g' switch, which has 6 11g miniPCI cards inside 2) the bridge/router, which has 2 23dBm 11b miniPCI cards inside
Vivato is (from what I hear) selling the snot out of both of these. The bridge/router lacks any co-ordination logic. There are 'tricks' that can make it work, but I can't expose them here (further than what I have).
NFW for you, but others need this.
No, they just don't understand why it doesn't work. Amusingly, Matt Peterson and Tim Pozar though they were going to use 3 cards per Soekris board, and 3 boards per cause while they built out their network.
I don't know about the details of your example -- and without them this example is useless. If they were using 200mW senao cards, then they would have big problems because the onboard amp puts out allot of noise -- but this does not happen with the 5GHz Ath cards.
Sorry, its not a PA NF issue (and the Senao cards are no worse than many others).
But it is a in-channel noise issue (due to operations on the adjacent or alternate channel, and the 23dBm tx power of the senao cards makes things worse, but (functionally) better than using a large antenna to generate the same EIRP, because that antenna gain will amplify the incoming signal as well, which will raise your in-channel noise power.
The comment sounds puzzling considering that you worked for a company that put six radios in an AP -- Vivato I think.
I've explained the differences at some length.
Then they quietly admitted that it doesn't work like that.
And these were 11b cards with an I/F section, so the ACR (adjacent, not alternate) was like 41dB. The 11g/11a card specs are much, must worse.
> It does appear a bit extreme, but people said the same when
we made the four port mpci to pci -- and they sell quite well.
I'm sure you'll sell a lot of them to people who don't get it.
You sound a little arrogant -- you must be so clever to be the only one who gets it, and you have never experimented or even touched this equipment. If we only had more people in the world like you.
I used to think like you do now. No really. I was a software guy (still am), who though he understood RF becaue he passed E&M physics.
Then some very kind people (who happened to work for me) explained it to me. One of them just took a job as Intel's new CTO in their wireless division, and is world-renowned for his knowlege of all matters RF.
Vivato was a 2 year period in which I probably obtained most of a 4 year degree in RF issues. I'm not an expert my any means, but I've been down the path that your customers are facing.
I also watched a lot of money get wasted on "multi-channel" operation. By "a lot" I mean something well north of $50 million. Its all in the blog.
Lots of people run dual 11g cards in a single AP as well. They don't get it either. The comment about "extra capacity" is especially amusing. IALMAO.
I have only tried on non overlapping frequencies on four and more radios on 5GHz.
I think I've showed this. If you mean that you've run on four "non-overlapping" frequencies in a single (U-NII) band, then I challenge you to reproduce the results "at range". I'm confident that you can't (without a lot of additional filtering).
Also, I have found the 11g doesn't do well with 11b. We have an 11g only setting that does help some -- in general, not pertaining to the multiradio discussion we are having here.
Actually its very nearly the same issue, especially if you're attempting multi-channel operation.
There are a lot of stupid people in the world. Might as well take their money, right? I take my hat off to you for supplying what people want, but don't need. I'm sure you'll sell a lot of these.
This line of argument won't get you far in economic theory or philosophy. Again, for someone who has never touched these cards and made a setup, you can't expect to be taken seriously.
I don't need to touch your 4-way or 8-way adapter to understand the issues with running multiple miniPCI cards, especially on multiple channels.
Nothing you can do at the PCI bus 'layer' can solve the issues.
Been there, done that, and I trashcanned all the shirts when I left Spokane.
The reduction in available power to each slot is also ... troubling.
What "power" are you talking about? PCI standards support this amount of power -- read the specs. The onboard power controller changes 5V to 3.3V -- and very efficiently.
Sure, but each slot only gets 2.5W @ 3.3VDC, that makes for 750mA, if my math isn't wrong. Thats pushing it for an Atheros 5212 (or 5312) based card.
Sorry to be attacking the messenger (it is not good debating strategy -- but I have been attacked above).
Do you know anything about 802.11 radios and mpci standards!!!! If the rest of you comments are based on similar research -- then it is all BS.
See the mPCI v1.0 standards and you will find that the max power consumption is 2W per mPCI slot -- and the makers of mcpi are not going over it (except for the senoa prism mpci).
Check the current draw on the Atheros card you sell while its in rx or tx mode, then report back. Yes, you'll make a 'duty cycle' arguement, which is fine. I only said that it was "close".
See the PCI2.2 standards and
you will see that the max power usage per PCI slot at 5V is 20W. So, 8x2=16W and consider that we have an efficient power controller (probably about 85% efficiency -- I would have to check), then we will be below the 20W PCI slot power limitation.
The issue is the 2.5W max power per slot. At 3.3VDC (the only supported voltage on miniPCI), thats 750mA. Right?
I never thought you were making it up. But I think you've not been honest with your customers about what is possible, and what isn't.
That is a very strong statement you are making. I think you have had too much coffee or something at one time. See the response to Jack Unger for more on what I say is possible. Personal attacks are not the correct way to address technical issues.
I'm sorry that you think I'm attacking you personally. I'm not. I have offered opinions, which you have mistaken as attacks, and for this I apologise.
I'm sure that many of your customers want an 8 slot board.
I'm sure you'll sell a lot of them.
I'm sure that many of your customers won't understand the issues.
My hat is off to you for putting the warning in your manual that Jack requested. With any luck, Google will pick-up this thread.
Jim
John www.mikrotik.com
Jim
John www.mikrotik.com
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Guess all we would need to do is mount a Micro-ATX 2ghz processor board at
the top of the tower, and be done with all the extra radios now! Thank John!
Who else in the US aside from Eje carries your products please? Can you list
all sources ?
JohnnyO
>From: "John Tully" <[EMAIL PROTECTED]>
>To: <[EMAIL PROTECTED]>
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John,
That is absolutely wonderful :-) but what do you suggest we use to power that puppy with? Do you have something with enough CPU horse power to push those 8 cards as I have started putting all my gear on the towers?
Thanks,
Mac
John Tully wrote:
RouterBOARD 18 -- 8 port mPCI to PCI board (Extreme)
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I think it's great to see this out now... If you've got sectors and
pass-through back-hauls, you've got 6. Then you've got a couple extra ports
for redundant backhauls or extra capacity.
-------------- Mike Hammett Intelligent Computing Solutions http://www.ics-il.com ---------------------------------------- John, Can I trade in my unused 4 port version :) To think I just recently bought a 4 port and needed 6. >From: "John Tully" <[EMAIL PROTECTED]> -----------------------------------------
