Fluctuating Airport Signal Strength

I'm working in an office where there are several Macs sharing an Airport.
Today the signal strength (as indicated by the Airport "thingy" on the
toolbar) is fluctuating. Other than today it always seemed to be at full
strength but today is varying between full strength and no strength, spending
most of the time at three-quarters strength. I've checked the other Macs in
the office and they are all at full strength and I didn't see any evidence of
fluctuation. Any suggestions as to what is happening?


-- James L. Ryan -- TaliesinSoft

"My dog never came across a bush he didn't like!"

 

I got exactly that symptom from two separate causes. Once, the antenna
connector in my iBook came a little loose, and as soon as I discovered
that and reseated it the problem went away. The other time confused me
greatly until I ran a WiFi "sniffer" program, which showed that a neighbor
had an access point on the same channel as mine. I changed my base
station to a different channel and all was well again.

Since yours is the only one having issues, I'd suspect the antenna
connection, or perhaps the AirPort card itself. It's possible that
there's a *very* localized source of interference, but I don't know what
it would be.

 

[commenting on my stating that the Airport "thingy" in the menu bar was
showing fluctuations]

Well, there are four arcs in the "thingy" and during what I've dubbed
"fluctuation" the number of lines that remain dark varies from 0 to 4. Also
the "time connected" figure comes and goes, disappearing when the number of
dark lines drops and reappearing when the dark lines return.

When the number of dark lines diminishes to none communication stops. But
given that this state only lasts for a second or two there has been no
effective break in communication.


-- James L. Ryan -- TaliesinSoft

"My dog never came across a bush he didn't like!"

 

[responding to my concern over fluctuating Airport communication]

Interestingly the variations that persisted throughout the afternoon have now
ceased. The Airport "thingy" in the menu bar is now consistently showing four
blackened arcs which, I presume, indicate maximum quality reception.


-- James L. Ryan -- TaliesinSoft

"My dog never came across a bush he didn't like!"

 

If you click on the toolbar icon, you'll see a choice called "Open
Internet Connect" ; that will show signal strength on a 15-bar scale.
There are third-party utilities (MacStumbler, iStumbler) if you need
more detail.

KeS

 

I had a similar problem with my home network (iMac, two Powerbooks, and
an ABS). Resetting the ABS solved the problem for me.

 

[commenting on my Airport weak signal query]

The Airport is about twenty feet away (through two walls) from the iMac
(about 4 years old) that has the Airport card.

Sometime last night (maybe around 10 PM) the weak signal problem stopped and
today everything seems back to normal. As of right now if I open Internet
Connect and look at the signal strength it is at the 13th of the 15 bars.


-- James L. Ryan -- TaliesinSoft

"My dog never came across a bush he didn't like!"

 

Entity James L. Ryan spoke thus:

Sounds like your garden variety multipathing problem (AKA "ghosting"). This
occurs when the signal reflects off of objects and interferes with itself.
You might try a different channel. In my case, I did a hard reset of the
base station which forces the transmitter to seek out the least noisy
wavelength. Presto! Multipathing no more! The ideal wavelength would be a
whole number multiple of the distance to the reflective surface.

This might sound bordering on the mystical, but the 2.4 gigahertz band has a
lot of weird behavior when it goes through walls. I operate through adobe,
most of which contains a wire mesh inside. I swear, the signal is affected
by cloud cover (ducting), dewpoint, ion bombardment and lord know what else.

-- K5ZN
http://www.qsl.net/k5zn/

 

Does anyone know if a 2.4 GHz phone can interfere with Airport. I have
an airport equipped iBook (G3/700 MHz), and I noticed that, if I used
it downstairs in our living room, I would lose my connection whenever
someone used our 2.4 GHz cordless phone. I don't have a lot of repeats
on this, as I've only had the iBook for about 2 weeks, but it was
pretty strange. My wife would call someone, and I would lose my
Airport signal. Has anyone else seen this?

 

Entity David Fritzinger spoke thus:

Yes, definitely. There are 11 channels, try some different ones.

-- Gnarlie
http://www.Gnarlodious.com

 

Now yet another mystery! Dave's posting above quotes a posting from Gnarlie
which in turn was a response to an earlier posting of mine. What is weird is
that Gnarlie's posting is inaccessible to me, and I wouldn't be aware of its
contents if it wasn't for Dave's quoting it.

I use Hogwasher for newsgroups. In the topic diagram Gnarlie's inaccessible
posting is shown as an "unidentifiable" link between my posting to which he
replied and Dave's which quotes him.

Son now the question is what could have happened that I can't access
Gnarlie's posting?


-- James L. Ryan -- TaliesinSoft

"My dog never came across a bush he didn't like!"

 

Yes, definitely. There are 11 channels, try some different ones.[/QUOTE]

I suspect my neighbor got one. My signal strength dipped mysteriously
one day and didn't come back until I changed to channel 11.

--
Walt Sellers
Computer Engineer For Hire
www.VirtualOutpost.com
- include the keyPhrase "WhoYaGonnaCall?"
in the body or subject of the message to get past the spam filters.
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
Meddle not in the affairs of dragons; for thou art
crunchy and good with ketchup. -unknown
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

 

<http://docs.info.apple.com/article.html?artnum=58543>

 

Yes. They both use the same spectrum.

 

Phones tend to center on channel 6.

A WiFi signal uses 22MHz of bandwidth, but the WiFi channels are only
5MHz apart, so when you use a given channel you overlap adjacent
channels with the strongest part of your signal being the channel number
you specify. If you have competing WiFi base stations using a channel
that overlaps with your 22MHz of signal, it will cut down on your total
throughput and may interfere with your range.

Using a utility like MacStumbler and APGrapher can help you check out
signal strengths of other WiFi base stations and the level of
interference.

Personally, I tend to use channels 1 and 11 as it stays away from 2.4GHz
phones and lot of times, other WiFi base stations default to channel 6
as well, so unless my neighbors configure their base station, it is
channel 6 (some base stations search for the best channel and use that
instead of a fixed default).

Bob Harris