Re: Intermittent signal

On Fri, 9 Nov 2007 15:05:48 -0500, meerkat
<meerkat.2zssoc@no-mx.wirelessforums.org> wrote:

>A friend is having intermittent wireless problems - signal fading,
>dropping out completely. I've checked with NetStumbler and the pattern
>is as follows:
>
>- A spike of signal every 121 seconds (-40 to -60db) for an irregular
> period
>
>- Followed by a block of steady signal (-25db) for on average 2 mins
>
>- then back to the spikes every 121 seconds

I don't understand. Is there a spike of "signal" or "interference"
every 121 seconds? I'll assume interference. Could you please
describe what you're seeing a bit better being careful to
differentiate between signal and interference? From where are you
getting your signal strength numbers?

-25dBm (not -db) is a very strong signal and is probably nearby. My
wild guess (probably wrong) is a streaming video system over wi-fi,
that buffers it's output in roughly 4 minute intervals. Look around
for a Tivo box with a wireless adapter.

>This pattern happened with two routers - an old BT wireless router and
>a new BT HomeHub, so it's not down to the hardware.

How about location? Can you move the router closer or farther away
from the nearest window to see if it's coming through the window?

Also, have you tried attaching a directional antenna to a client radio
and attempting to determine the direction it's coming from? If
difficult, a simple reflector will work.
<http://www.freeantennas.com>

>I've checked for obvious sources of radio interference but can't find
>anything obvious apart from a BT wireless phone base station and
>handsets which I unplugged from mains.

See list of possible sources at:
<http://wireless.wikia.com/wiki/Wi-Fi#Interference>

>Any ideas anyone? Any pointers would be gratefully received.

I have lots of ideas (and experience) but I need a better description.

--
# Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
# 831-336-2558 jeffl@comix.santa-cruz.ca.us
# http://802.11junk.com jeffl@cruzio.com
# http://www.LearnByDestroying.com AE6KS

Jeff,
I just wanted to take 20 seconds and say "thanks" for the information
you've been posting. I am brand new to wireless... having been a
computer hardware guy for 21 years. I fixed them, built them, sell
them and have kept them running for my customers for all those years.

Recently I've been dragged, kicking and screaming at first, into
wireless internet provision. So far I've only used Tranzeo Units in
the 900 MHZ band. I must say I am enjoying it immensely.

Here it is again 3 am my time here in Vancouver and this is the third
day in a row I've spent all night reading your stuff. I'm clipping
all of the goodies and studying like mad. Most of all, your posted
links to the various resources have added so much value for me I felt
I had to just go off topic for a stint to say thanks. It must be both
frustrating for you and a lot of work. But it is well appreciated!

thanks,
Nick.


On Sat, 10 Nov 2007 00:57:08 GMT, Jeff Liebermann
<jeffl@comix.santa-cruz.ca.us> wrote:

>On Fri, 9 Nov 2007 15:05:48 -0500, meerkat
><meerkat.2zssoc@no-mx.wirelessforums.org> wrote:
>
>>A friend is having intermittent wireless problems - signal fading,
>>dropping out completely. I've checked with NetStumbler and the pattern
>>is as follows:
>>
>>- A spike of signal every 121 seconds (-40 to -60db) for an irregular
>> period
>>
>>- Followed by a block of steady signal (-25db) for on average 2 mins
>>
>>- then back to the spikes every 121 seconds
>
>I don't understand. Is there a spike of "signal" or "interference"
>every 121 seconds? I'll assume interference. Could you please
>describe what you're seeing a bit better being careful to
>differentiate between signal and interference? From where are you
>getting your signal strength numbers?
>
>-25dBm (not -db) is a very strong signal and is probably nearby. My
>wild guess (probably wrong) is a streaming video system over wi-fi,
>that buffers it's output in roughly 4 minute intervals. Look around
>for a Tivo box with a wireless adapter.
>
>>This pattern happened with two routers - an old BT wireless router and
>>a new BT HomeHub, so it's not down to the hardware.
>
>How about location? Can you move the router closer or farther away
>from the nearest window to see if it's coming through the window?
>
>Also, have you tried attaching a directional antenna to a client radio
>and attempting to determine the direction it's coming from? If
>difficult, a simple reflector will work.
><http://www.freeantennas.com>
>
>>I've checked for obvious sources of radio interference but can't find
>>anything obvious apart from a BT wireless phone base station and
>>handsets which I unplugged from mains.
>
>See list of possible sources at:
><http://wireless.wikia.com/wiki/Wi-Fi#Interference>
>
>>Any ideas anyone? Any pointers would be gratefully received.
>
>I have lots of ideas (and experience) but I need a better description.

Rangefire Wireless <rangefire@bcfirst.com> hath wroth:

>Jeff,
>I just wanted to take 20 seconds and say "thanks" for the information
>you've been posting.

Blush... Y'er welcome. It's good to know that someone is actually
reading my stuff. However, I don't have a monopoly on wireless
knowledge and the industry is growing in all directions
simultaneously. You should probably look at other sources of info as
there are some aspects of wireless, where I'm lacking.

>Recently I've been dragged, kicking and screaming at first, into
>wireless internet provision. So far I've only used Tranzeo Units in
>the 900 MHZ band. I must say I am enjoying it immensely.

900MHz goes through trees fairly easily. However, there's a bit of
magic in doing that at long distances. Tranzeo or Trango?
<http://www.trangobroadband.com/wireless_products/m900s.shtml>
Maybe Waverider, which I hear is popular in Canada.

>Here it is again 3 am my time here in Vancouver and this is the third
>day in a row I've spent all night reading your stuff.

Computers and wireless are best done under cover of darkness. I'm
afraid I'm getting too old to do an all nighter. I used to work
through the night regularly. I can still do that, but the result is
that I'm a zombie for the next 2-3 days. It's not worth that.

>I'm clipping
>all of the goodies and studying like mad.

All of them? That will take more than one 3am session to read.

>Most of all, your posted
>links to the various resources have added so much value for me

I guess you mean the FAQ. There's quite a bit of good stuff in there.
<http://wireless.wikia.com/wiki/Wi-Fi>
Feel free to add anything you find useful. I would post my bookmarks
file, but I would first need to clean out the pornography and junk.

You might want to download the PDF version of "Wireless Networking in
the Developing World" at:
<http://wndw.net> (2MB or 12MB)
The "book" is apparently assembled from various contributors with
widely varying styles and abilities. It's very spotty in some areas,
and excellent in others. 254 pages. I'm reading it erratically as
time permits.

>I felt
>I had to just go off topic for a stint to say thanks. It must be both
>frustrating for you and a lot of work. But it is well appreciated!

The only part that's really frustrating is the huge number of computer
users that for some unknown reason, seem to think that computer
problems can be solved without supplying any numerical specifics, such
as maker and model number. An additional overlapping group seem to
lack the basic skills necessary to describe a problem or experience.
(Note: I read the headers to guess if English is not their first
languaage). I spend as much time and effort interrogating such people
for basic information, as I do trying to answer the questions. The
frustration is not in the effort involved, but in my dissapointment
with their written communications skills.

Anyway, enough complaining. Thanks for the good words, have fun, and
try to ease up on burning the midnight oil.

--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On Sun, 11 Nov 2007 09:31:57 -0800, Jeff Liebermann <jeffl@cruzio.com>
wrote:

>Rangefire Wireless <rangefire@bcfirst.com> hath wroth:
>
>>Jeff,
>>I just wanted to take 20 seconds and say "thanks" for the information
>>you've been posting.
>
>Blush... Y'er welcome. It's good to know that someone is actually
>reading my stuff. However, I don't have a monopoly on wireless
>knowledge and the industry is growing in all directions
>simultaneously. You should probably look at other sources of info as
>there are some aspects of wireless, where I'm lacking.

Yes .. but remember. I started a few days ago. You were probably
taking things apart since you were three. I've managed to learn the
basics... very very basics so far. There is so much to learn and no
books entitled "Networking for former Stone Masons". It is an
exercise in hyperlinking. My organizer is on a 4 GB Sandisk U3
program called EssentialPIM. I cut and past much of what you say,
plus all of the links and links that others post. Then I spend oh...
about 8 hours at the end of my day learning. Everytime I find a
term or concept I don't understand, I google it and assimilate it.
Sometimes that minor deviation from my original track takes me off
course by four to five hours. I listen to Baroque music while doing
this. It seems to let me absorb the material faster ... and with
better retention. Don't know why. Just does.

>>Recently I've been dragged, kicking and screaming at first, into
>>wireless internet provision. So far I've only used Tranzeo Units in
>>the 900 MHZ band. I must say I am enjoying it immensely.
>
>900MHz goes through trees fairly easily. However, there's a bit of
>magic in doing that at long distances. Tranzeo or Trango?
><http://www.trangobroadband.com/wireless_products/m900s.shtml>
>Maybe Waverider, which I hear is popular in Canada.

I'll check out Waverider. But mine is Tranzeo. http://www.tranzeo.ca
They are publicly traded. The 900 MHZ system costs me $360 ($300
Canadian). For my customers it is a $500 price tag after they've
purchased their Cable service at the nearest spot. Of course... I do
the site survey first and tell them where to stick the antenna!
>
>>Here it is again 3 am my time here in Vancouver and this is the third
>>day in a row I've spent all night reading your stuff.
>
>Computers and wireless are best done under cover of darkness. I'm
>afraid I'm getting too old to do an all nighter. I used to work
>through the night regularly. I can still do that, but the result is
>that I'm a zombie for the next 2-3 days. It's not worth that.
>

It is worth it to me. I have never found anything I like more than
this. Two ex wives will vouch for that. I was a jail guard for years
so the nights don't bother me. If I go until 4 am, I just sleep til
12 noon.

>>I'm clipping
>>all of the goodies and studying like mad.
>
>All of them? That will take more than one 3am session to read.
>
>>Most of all, your posted
>>links to the various resources have added so much value for me
>
>I guess you mean the FAQ. There's quite a bit of good stuff in there.
><http://wireless.wikia.com/wiki/Wi-Fi>
>Feel free to add anything you find useful. I would post my bookmarks
>file, but I would first need to clean out the pornography and junk.
>

It would be no different than mine in that respect.. I'm sure...

>You might want to download the PDF version of "Wireless Networking in
>the Developing World" at:
><http://wndw.net> (2MB or 12MB)

Great tip! Thanks.

>The "book" is apparently assembled from various contributors with
>widely varying styles and abilities. It's very spotty in some areas,
>and excellent in others. 254 pages. I'm reading it erratically as
>time permits.
>
>>I felt
>>I had to just go off topic for a stint to say thanks. It must be both
>>frustrating for you and a lot of work. But it is well appreciated!
>
>The only part that's really frustrating is the huge number of computer
>users that for some unknown reason, seem to think that computer
>problems can be solved without supplying any numerical specifics, such
>as maker and model number. An additional overlapping group seem to
>lack the basic skills necessary to describe a problem or experience.
>(Note: I read the headers to guess if English is not their first
>languaage). I spend as much time and effort interrogating such people
>for basic information, as I do trying to answer the questions. The
>frustration is not in the effort involved, but in my dissapointment
>with their written communications skills.

I'm not so sure it is a matter of them not thinking it through and
adding the essential details. This whole area is one that is mastered
by those who are able to apply a tightly focussed mind to a well
defined problem. Their "thinking" IS the problem. If they had the
attetion to detail to provide you with the necessary detail up front,
then I suspect they would not have the problem. Thier thinking would
have got them through the issues. Also, with youth comes impatience.
Many of them are not old enough to understand working a problem
through.

>Anyway, enough complaining. Thanks for the good words, have fun, and
>try to ease up on burning the midnight oil.


Thanks again..
Nick.