Data on chipsets

Is this one question or four questions? If one, you have all the right buzzwords, but they're all mixed together into an unintelligible mess. Are you a student or beginning engineer who has just been assigned a research subject where you haven't even begun to read about the basics? If so, it would helpful to know what you're trying to accomplish.

Hmmm... Looks like you're in Guangzhou China.

You really should do your own homework.

Wireshark and Ethereal are packet sniffers. They will sniff anything that resembles ethernet down to the MAC layer. It will also sniff other protocols (Novell). There are no requirements for a specific chipset other than it supports ethernet.

Netstumbler is a wireless packet sniffer that talks to the NDIS driver under Windoze. Any chipset that has an NDIS driver will work.

Management software usually means SNMP. There are huge numbers of SNMP management applications. The only requirement is that the chipset supports ASN.1. This is usually not done by the chipset, but rather by the support chips. Any chipset that can be interrogated for performance statistics will support SNMP.

Windoze, Linux, FreeBSD, and OS/X are operating systems. It's a little like judging a book by its cover. What under the cover is what's important. Once you get past the fancy cover and user interface, all operating systems are very similar by the time they talk to the chipset and run SNMP management software.

Reliability? Is that like 99.999% uptime? Perhaps it's production failure rate? Maybe ability to actually deliver chips on time? Maybe reliably delivering something close to their stated specifications? What manner of reliability were do you need to know?

See the FCCID web site for specific products that use the chipsets for transmit power. Note that many manufactories use external power amplifiers with plenty of surplus gain because the chipset output tends to vary all over the place. (This is not totally the fault of the chip, but may also involve the PCB, passive components, and mechanical creativity.)

Receive sensitivity is a joke. Eveyone lies. In most cases, they measure the NF and gain of the receiver front end, and calculate the theoretical sensitivity based on the slowest speed and modulation type. Few have ever been able to come close to the alleged receive sensitivity because the all too necessary external components will reduce the sensitivity. In addition, few individuals have the necessary BER/PER generators and signal sources necessary to actually measure RF data sensitivity. So, the manufacturers just quote the exact chipset specs and pray that nobody will call their bluff.

I started graphing some of the alleged sensitivities at:

It appears that DLink has actually measured the RX sensitivity on most of their access points. Note that their measurements are about 6-10dB worse than an example of just copying the chipset specs (Ubqt Lightstation 2).

And you received an answer? Impressive. They won't talk to me unless I have a huge purchase order pending. I can't even get data sheets without signing an NDA (non disclosure agreement).

Those are not radios or chipsets. That's also a very incomplete list of wireless chipset manufacturers. Use Google to find a list of supported wireless devices and chips.

Ummm.... I don't know of any chipsets that put out that much power. Most are about 50mw maximum. If you want 400mw, it requires an external amplifier chip.

To do what?

Nope. You haven't disclosed what you're trying to accomplish.

Jeff Liebermann wrote in news: snipped-for-privacy@4ax.com:

Are you related to that character from the old Sat. Night Live show, the "computer guy"? :-) Same thing 99.5% of the other posters here are here to accomplish-to connect to an AP with max. signal strength. Seems clear to me or do I have to follow some kind of writer's format, i.e. Question I.) a.) i.)

I got tired of Guangzhou so I just flew over to Romania. Maybe you'll like that location better?

Ok so chipset is irrelevant as far as using WS or Etheral is what you're saying.

Well, seems to me I have read numerous threads about which radio chipsets that are supported by netstumbler. Discussions in which the participants say don't use that radio as the chipset is not supported by netstumbler. Maybe I don't understand what they are saying then.

I am guessing the SNMP is what the programs I am referring to are written for. So I am thinking that you're saying chipset is really not the determining factor as to whether or not a radio is likely to have a good program to control it's connnections, scanning, etc.

Already know what OS are. So are you saying that chipset is irrelevant when selecting a radio for a specific OS?

Reliability is just what it says. Are you saying that all chipsets are equal in terms of their propensity to enable the radio to connect and maintain a stable connection? Again as with the vast majority of posters to this group, I am asking about what chipsets make for a good radio. Or are you saying that chipset is also irrelevant to answering that question. Client Adapter--->connect to distant municipal AP; maintain a good stable connection

I don't have the ID info, I guess I can get it though. What is the url for the FCCID web site? I guess the only thing that really matters is how much warranty they will give me so I can return the product and get a refund if it is not any good. So, from your answers, I guess I didn't really need to post here.

Ok, so again warranty is the only criterion to use to buy or not buy.

So does your testing cover any of the chipsets mfg. I have mentioned?

I have had good luck getting answers. I never hurts to ask, even if your not an expert and don't fully understand all the engineering behind everything.

supported for what? first your saying chipset doesn't matter, now you're saying I should look up which are supported. Which is it? They are radios, I just haven't given the brand names here because the suppliers imo don't deserve the free advertising. I am not interested in getting a complete list. I am only interested in finding one that will work best for me and the purposee I have already mentioned here and in my o.p.

They don't mention amplifiers directly, except in the case of the "custom" realtek model which I think is 500mw. Don't know what they mean by "custom" exactly.

What do you usually use antennas for? To improve range and reduce noise levels. I will use a parabolic reflector behind a pole antenna connected to one of these usb radios.

Yes I have, I think your over analyzing things and not seeing the forest through the trees. This is not a doctoral dissertation inquiry, I am just a home user trying to get a few answers on what to buy.

Most home users don't feel any inclination to try and run Wireshark on a municipal AP. Most home users would have asked the Linux and FreeBSD forums for what wifi worked for them or failing that Google.

It would have narrowed down your choice of chipsets or adapters. note that the chipsets do have numbers e.g. AR5210, AR5211, AR5212, AR5413, AR5414 not just Atheros. You also did not mention which 8187 chipset you were referring to, l or b.

Quoting a chipset number is not advertising the wifi adapters brand name, most home users are not interested in which chipset is used and they can cover a wide range of manufacturers.e.g.

If you have already narrowed it down to 3 "unknown" devices then you will have checked that win98se drivers are available for them. If you have the FCC ID no's for those devices you can check out the test reports at

If you have done your reading on Netstumbler then you must know that you need a "Hermes" chipset to get it to work in win98se.

?

LR wrote in news: snipped-for-privacy@bt.com:

I'm not a typical home user, :-)

Ha they're even worse than this group for having computer guy types with whom it is impossible to get an answer to questions w/out getting into a pissing contest.

Thanks for the links. I know they have numbers, it was hard enuf to just get the mfg names. These vendors are often ignorant of what they are selling and they assume that people will just buy on their advertising hype, because most do.

Read my post again, never said that quoting the chipset number was advertising, just explaining why I am not supplying the link to their ad pages.

Thanks for the link, I KNOW all this stuff is on the web, but I cannot find time to search for it all, sorry.

Yes, so why is Jeff claiming it makes no diff?

I really do not understand this group. I thought it was supposed to promote wifi use, but every time I post here all I get, sometimes with actual answers, is slammed. If I knew everything about it and had time to research everything I wouldn't need this group, now would I? Thanks again for the links.

The problem here is that there are so many distro's and build versions that you need to ask on their forums for info on wifi adapters that work "out of the box", o.o.b,, on the version and build that you are interested in. If it doesn't work o.o.b. there is a better chance that someone there will have either a found way to get it to work or know that it doesn't.

If we don't know the chipsets or adapters how do you expect us to help?

Because Netstumbler talks to the NDIS 5.1 driver not directly to the card (unless you have an old Orinoco card with a Hermes chipset). If there's a driver, Netstumbler will work. The purpose of the NDIS driver is to provide a standard interface that hides the underlying chipset from the user application. As long as the driver works, you don't need to know what chipset is under the driver. Unfortunately, there are broken chipset and broken drivers, so I can't claim that everything works as advertised. For example, some chipsets lie about signal strengths. You might get more specific answers in the Netstumbler forum.

I've had my best results with various Atheros chipsets. They're also available open source for Linux using the MadWiFi drivers and others:

Yep. You're getting slammed by me for spending perhaps 2 minutes writing a mix of unrelated questions. You supplied only a vague clue as to what you're trying to accomplish and what you have to work with. Perhaps others are more claravoyant, but I had difficulties determining what you're asking.

When I can't supply a specific answer, I try to explain how things work. Perhaps you mistook the lecture mode for some form of criticism. That wasn't my intent. I was trying to supply the basics and let you fish out what parts are relevent to solving your problem. If that's not possible, try reframing your question or supplying additional detail.

True. I would expect you to do the basic research (i.e. Google) and spend a few minutes assembling a series of usable questions. Were you to spend the same amount of time I've spent crafting a reply, you probably could have answered much of your badly stated questions without our help.

Incidentally, one problem you're probably going to run into is that current products and some chipsets may not have Win98SE drivers. It's also becoming difficult to find supported Win2K and NT4 drivers.

Win98SE doesn't use NDIS 5.1

If there is no NDIS for 98, then you should probably get the Orinoco classic card with Hermes chipset. I used to have one of those. B only, but there is a driver out there that will let it do WPA security. External antenna connector is atypical, I remember.

I believe that the difference in sets that play well with NetStumbler is whether they have to use the NDIS driver or not. With the NDIS driver, it does not seem to report noise level, just a relative signal.

I remember that they had some list on the NetStumbler forums where users report what has worked for them. Long, complicated list, to be sure.

Staying with Win 98 is likely more trouble than it's worth, but I imagine you have your reasons for struggling with it. Think about whether it's really necessary for you to run a pre 2000 version of windows.

It sounds like when you say managment software, you are referring to what others call wireless utilities, not SNMP. Windows XP has one built in that I prefer, called "Wireless Zero Configuration" Most cards come with one, but I would check which ones work in 98. Again, the Orinoco should be a good bet, it's old. Each OS would use a different utility, I imagine.

Steve

Thanks for the additional info....

seaweedsl wrote in news: snipped-for-privacy@j18g2000prm.googlegroups.com:

I have to use USB, computer does not have pcmcia.

Happy with 98SE on this old box. When it misbehaves I just restore from image. If I switch OS, I will go to non-windows, which is one reason I said in my original post win98se, linux and/or bsd. I will run a dual boot system with win98se and one of the other two.

Yeah, that is what I was referring to. I have software for my laptop that works fine with a senao card, but I need usb for the other machine. Besides these radios I am looking at LOOK good on the surface and USB avoids antenna cable losses and is very portable. One problem is that the vender either does not answer emails or is sloowwwww, so that is a red flag. I really do not see much differences between the various flavors of Windoze, they are all pretty flaky.