Multipath WLAN problem?

[Joerg]

Jump online and find and buy a pair of better antennas. Problem solved.

Signal strength ain't the problem, plenty of signal.

You also may be able to download third party firmware for it that allows
you to boost the power beyond the factory, consumer accessible setting
window.

Also make sure you are using a newer, more secure access methodology.
The old simple password, open broadcast method is insecure. Limit
wireless ports to the number you use. You can also turn it on and off via
an operating PC or even via web access, depending on your router.

Well... it isn't 'true diversity'. You can also buy a long coax that
allows you to place an antenna away from the actual router.

That's what I am afraid it's doing as well. Maybe it just slowly
switches between the antennas and on one of them it just doesn't see
some PCs.

The best thing to do is buy on ebay, an already upgraded router that
runs Linux and the WRT firmware upgrade that allows you professional
router setting and power levels on your consumer level router.

That router is: The world famous Linksys (Cisco owned) WRT54GS v3 for
max internal memory and CPU speed capacity. Mine was about $79 IIRC,
shipped. I upgraded the firmware on it as soon as I got it, so I know it
has nothing on it tucked away somewhere in the settings (these sellers
are legit).

Anyway, you can boost the piss out of it, if the new antennas don't
work.

http://shop.ebay.com/?_from=R40&_trksid=m38.l1311&_nkw=linksys+wrt54g&_sacat=See-All-Categories

Well, I'm not giving up this easy

 

[Joerg]

Maybe tack against the wind and -reduce- the Tx signal strength?. I.e
hamstring some of the strong contenders fighting to open the door.

Who wants to open the door? Other than our signals there really ain't
much to be seen. A wimpy signal on Ch1 (cordless phone) and a neighbors
WLAN router above Ch6. That's pretty much it.

 

[SoothSayer]

That's what I am afraid it's doing as well. Maybe it just slowly
switches between the antennas and on one of them it just doesn't see
some PCs.

It usually uses the one most used as a favored stick kind of thing.
Again, I doubt that it is 'true' diversity.

 

[SoothSayer]

Signal strength ain't the problem, plenty of signal.



That's what I am afraid it's doing as well. Maybe it just slowly
switches between the antennas and on one of them it just doesn't see
some PCs.



Well, I'm not giving up this easy

That unit you have may well have 3rd party firmware for it that boosts
it as well, and gives you other options.

http://www.dd-wrt.com/dd-wrtv3/index.php

 

[whit3rd]

After moving the office one of the things that doesn't work reliably
anymore (besides a dead printer and a dead Tektronix) is the WLAN. It's
a Linksys BEFW11S4 router with the routing parts disabled, to act only
as a wireless AP.

Actually not just an AP, it's your wireless host (unless
you have some other always-on central unit that gives
a name and other attributes to the wireless environment).

As host, it determines the channel (they go from 1 to 12 in
the US), and it might be that some neighbor is using the
same channel (and having the same problem with your
interference). Try different channels, it may help.

Most recent firmware for the BEFW11S4 is 1.52.02,
last time I checked; updating is usually a good idea, too.

 

[Rich Grise]

I know. You had snipped Jan's remark that he doesn't believe in
multipath which I was responding to. If he had lived in this neck of the
woods he'd know different. ATSC in heavy multipath is the pits.

Could you please include a notice in the subject line when you're
trollfeeding?

Thanks,
Rich

 

[JosephKK]

Signal strength ain't the problem, plenty of signal.

Well, I'm not giving up this easy

Here is a wild, off-the-wall idea: Run a chunk of low(er) loss coax
from the router to the lab and put an antenna in there. Mught want to
be thoughtful about antenna design and placement so as to minimize
intereference with the rest of the house.

 

[UltimatePatriot]

Could you please include a notice in the subject line when you're
trollfeeding?

Thanks,
Rich

You're a goddamned retard, Grise. I hope weed does get legalized out
here, and I hope *you* die before you ever get to smoke legally in this
great nation of ours, you retarded little troll bastard.

 

[SoothSayer]

Here is a wild, off-the-wall idea: Run a chunk of low(er) loss coax
from the router to the lab and put an antenna in there. Mught want to
be thoughtful about antenna design and placement so as to minimize
intereference with the rest of the house.

Might the router be sensitive to line length?

Get the new firmware from DD-WRT. It is v24. It allows a HUGE boost,
so more, better signal WOULD work in this circumstance. Trying to get
more out of it with the current firmware is why it falls on its face
currently. There is a HUGE set of parameters to adjust. Just like on a
pro router.

This router runs Linux too. There are routers that will read USB
memory devices too. Some allow tweaking of the CPU speed. Mine does.
Find the right legacy router, that runs Linux, and you will have no
problem finding one on ebay that already has the DD-WRT loaded onto it,
as it is the most popular item among gamers and geeks. 200mW is way
better than 40mW. Likely about $70.

THAT IS THE RIGHT ANSWER TO YOUR PROBLEM.

 

[JosephKK]

Doesn't help. Again, signal strength ain't the issue. I did make a
reflector and got a fat >10dB boost. This did not increase the link
reliability by one bit.

Signal strength was not the point at all. You might also want to
place some 377 ohms per square resistive material surfacing in
strategic places also.

I guess I must open it and chase bad electrolytics. Opening that thing
is a bear.

If you wish, i do not think it will help though.

 

[SoothSayer]

If his problem is multpath distortion, all the power in the world won't help
him.

His ROUTER in his HOUSE, a LOCAL setting is NOT experiencing multipath
distortion!

At worst, it is having no problem sending a signal (the router). The
laptop or whatever at whatever location just has such a poor damned
antenna and weak transmitter that it cannot SEND its signal BACK to the
router well enough. THAT is the most common problem with being "out of
range", NOT ANY kind of multipath. It usually makes itself known by a
failure to get a handshake, which in WLAN world is 'signal strength
indicator bars', which do not appear without 'handshaking' succeeding.
This guy has had fucking mutilpath on the brain so long he likely has a
skull sized tumor in place of his brain!

 

[JosephKK]

His ROUTER in his HOUSE, a LOCAL setting is NOT experiencing multipath
distortion!

At worst, it is having no problem sending a signal (the router). The
laptop or whatever at whatever location just has such a poor damned
antenna and weak transmitter that it cannot SEND its signal BACK to the
router well enough. THAT is the most common problem with being "out of
range", NOT ANY kind of multipath. It usually makes itself known by a
failure to get a handshake, which in WLAN world is 'signal strength
indicator bars', which do not appear without 'handshaking' succeeding.
This guy has had fucking mutilpath on the brain so long he likely has a
skull sized tumor in place of his brain!

Tell us, just what is the wavelength at 2.45 GHz. Just how much path
difference is necessary to have negative recombination of waves. Show
us credible explanation on how it impacts symbol recognition.

Oh, do remember that the specific environment is vastly reflective.

 

[Joerg]

On Fri, 27 Feb 2009 14:06:34 -0800, Joerg

[snip]

I guess I must open it and chase bad electrolytics. Opening that thing
is a bear.

Efficient use of your time ?

Of course not during work hours. I'd do that in the evening. My wife is
crocheting teddy bears for Romanian orphans right now, lots of them.
Since I can't crochet I'll just sit next to her, some nice beverages on
the table, and take the router apart. Why? I hate throwing stuff away,
we aren't good stewards of the earth if we keep doing that. Those things
are never really recycled. Crunch -> landfill.

And yes, I still repair a radio when it breaks. Same reason as above.
But there is a whole 'nother one: You learn incredibly about cost
efficient design and packaging when taking mass products apart that way.
This is know-how I can really use in my business. It's tought nowhere else.

BTW I did learn crocheting in elementary school because we didn't have a
shop for the boys to learn wood working. But forgot it all by now.

 

[SoothSayer]

Tell us, just what is the wavelength at 2.45 GHz. Just how much path
difference is necessary to have negative recombination of waves. Show
us credible explanation on how it impacts symbol recognition.

Oh, do remember that the specific environment is vastly reflective.

If such distortion at such frequencies were such a problem, we would
all still be using low frequency RF schemas. We are not. Nor is the
military factions of the world.

I'll give you one guess as to what one of the reasons is. It is
related to wavelength, and diminished susceptibility to such problems as
wavelength decreases. That is just ONE of the reasons.

Even if it were a steel rat's maze with the antenna and receiver inside,
it would not have a problem, much less larger structures.

You were saying?

 

[AnimalMagic]

On Fri, 27 Feb 2009 14:06:34 -0800, Joerg

[snip]
I guess I must open it and chase bad electrolytics. Opening that thing
is a bear.

Efficient use of your time ?

Of course not during work hours. I'd do that in the evening. My wife is
crocheting teddy bears for Romanian orphans right now, lots of them.
Since I can't crochet I'll just sit next to her, some nice beverages on
the table, and take the router apart. Why? I hate throwing stuff away,
we aren't good stewards of the earth if we keep doing that. Those things
are never really recycled. Crunch -> landfill.

And yes, I still repair a radio when it breaks. Same reason as above.
But there is a whole 'nother one: You learn incredibly about cost
efficient design and packaging when taking mass products apart that way.
This is know-how I can really use in my business. It's tought nowhere else.

BTW I did learn crocheting in elementary school because we didn't have a
shop for the boys to learn wood working. But forgot it all by now.

I know. Been there, done that. After all I AM a registered Girl
Scout ;-)

...Jim Thompson

I got kicked out of scouts for eating brownies.

 

[[email protected]]

If its not the PSU caps, find some Echosorb sheets.



Steve Roberts

 

[Nico Coesel]

Yep, just like this dreaded ATSC we'll get in June :-(

I wish WLAN had an option in the protocol where you could set it to 300k
or so in order to ruggedize a connection. But it's always full bore.

The more expensive units can do that.

 

[SoothSayer]

You are clearly lost trying to talk about general case.

You are 'clearly' retarded in making assessments, and have no place
doing so, asswipe. The rat's maze example was ALL about your 'path
difference' question. When you're all done bitching about all this stop
to remember that these are digital packets being sent back and forth. The
industry has been pretty good at making that happen, and one person
constantly pitching a bitch about all his problems being due to multipath
distortion pretty much gets shot to hell the moment the WLAN handshake
takes place between the two points.

Here we have
a specific case where the situation is different.

No. You have a case where the claimed problem has been claimed to be
different than the standard case. That doesn't mean that it is, nor does
it mean that the observer is making the proper observations, nor does it
mean that he is qualified to make any such observations. Bitching about
multipath is common with this guy, and that should set an alarm flag for
everyone, but doesn't for some reason.

BTW answer the
wavelength question. (Hint: c~=3e8m/s)

I don't need a primer, dumbfuck. I've worked with diversity receivers
in this band for five years at least, ending a few years ago.

True diversity has signal processing which detects any multipath and
uses that as a factor in determining the best antenna to use for a
signal. It also has the capacity to cancel or ignore the reflected
signal components. It doesn't just pick the highest power level signal.
It picks the BEST signal. WLAN routers do NOT perform their claim of
'diversity' between the two closely spaced antennas on their router case
the same way the true diversity industry does.

2ndBTW you could try to
maintain thread context instead of speaking to only one post in a
thread.

First off, I do not need your fucked in the head 'you gotta post like
this' stupidity. 2ndoff, you can **** off trying to tell folks what to
do with their posting in Usenet.

Look, asswipe, I was referring to multipath, idiot! I have posted into
this thread several times and ALL have been on topic and to the thread,
you idiotic piece of shit.

I was also referring to the solution the dope needs, you dopey,
no-you-are-NOT-a-moderator IDIOT! Not that I need to subscribe to your
retarded assessments for reply criteria to begin with. In other words,
you retarded asswipe, **** YOU. **** off and die! You stupid ****.

 

[Joerg]

If its not the PSU caps, find some Echosorb sheets.

Do you think these routers can hiccup from their own RF echoes? It
almost seems like that but somehow I couldn't quite believe it. But
maybe it does because this building is full of hard RF reflectors,
aluminm-backed insulation in all the interior walls.

 

[[email protected]]

My bet is you have a echo enhancing chamber and are getting RF pattern
issues. Does anything change if you "load" the room by adding people
or moving around? Can you put a leaky dummy load on instead of a
antenna? Do you have any good quality microwave coax or attenuators
laying around? Set up a loosely coupled cable link between your two
rooms and see what happens. I know, by law its supposed to be a hard
to get connector, so try indirect coupling of the cable, ie a passive
repeater.

If I wanted to jam direct sequence spread spectrum, I'd add pulses
1/4 bit time leading and 1/4 bit time lagging. While I doubt your room
has any where near enough Q to ring that long, somewhere your getting
RF intermod or a reflection effect the system doesn't like. Other
things come to mind like desensing the receiver, bad or saturated
VSWR sense circuit etc. I have no idea if a modern LAN even looks
at its reflected power, but its something I'd check. Are you close to
a army base (NTIA 2.4 ghz primary allocation) or someone using RF
heating?

Lets start with basics Take the unit(s) outside and perform a
simple range and operations test. Leave it run outside a while. This
signal should only be a few mW to a few 10s of mW, so desense is
unlikely, but possible. You are using the factory antennas right?

Occam's Razor says the problem is usually something basic or a
malfunction. My rule has always been if you don't have diagnostics,
you start "playing" till you find something. Download Net Stumbler
and if it gets you better diagnostics.

Steve