Reliability of wireless connection?

[root]

I have a requirement for a 24/7 wireless connection to a network.
I have tried various combinations of pci/pci-e wireless cards and 80211g
or 802.11n. All my attempts have used wicd to open the connection.

In one case the computer is in the same room as an AT&T U-verse
gateway. In another case the computer is two walls away from
a linksys router.

My problem is dropouts. It seems that I am averaging more
than one dropout every 24 hour period.

To use one setup as an example: linksys wrt120N router,
Ralink corp. RT3060 Wireless 802.11n 1T/1R network card
running Slack 14.

Signal power at the computer is 65% under wicd.

iwconfig shows:
wlan0 IEEE 802.11bgn ESSID:"2WIRE667"
Mode:Managed Frequency:2.437 GHz Access Point: 68:7F:74:7E:4B:5E
Bit Rate=11 Mb/s Tx-Power=20 dBm
Retry long limit:7 RTS thr:off Fragment thr:off
Encryption key:off
Power Management:off
Link Quality=42/70 Signal level=-68 dBm
Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
Tx excessive retries:0 Invalid misc:15 Missed beacon:0

The ESSID 2WIRE667 is bogus, that is just how I set up the linksys router.

Repeated runs of iwconfig reveals the signal level changes significantly
over a period of a few minutes. I got the -68dbm before starting this
message, just now I reran iwconfig and got -74dbm.

A google search for "linux wireless dropout" yields about 200,000 pages
but none of the first few dozen entries seems applicable.

I would appreciate any suggestions from people that have addressed
wireless dropouts.
Thanks.

[Michael Black]

On Tue, 14 May 2013, root wrote:

> I have a requirement for a 24/7 wireless connection to a network.
> I have tried various combinations of pci/pci-e wireless cards and 80211g
> or 802.11n. All my attempts have used wicd to open the connection.
>
> In one case the computer is in the same room as an AT&T U-verse
> gateway. In another case the computer is two walls away from
> a linksys router.
>
> My problem is dropouts. It seems that I am averaging more
> than one dropout every 24 hour period.
>

I have no idea. Make sure the signal is strong. When I first did wifi in
October, I noticed a sluggishness (which I read to mean packet resends)
until I reoriented the antenna at the back of the computer (it's a PCI
wifi card). Signal stremgth was up, and the sluggishness gone. Then it
happened again when I was fiddling with cabling; once I rearranged things
again the problem went away.

Michael

[root]

Thanks for responding, but I may have found a solution. This is
what I did:
In a console:
edit /etc/wicd/manager-settings.con
and change the "wired_connect_mode" to 0
instead of 1.

Then start wicd-curses and select your network. Press
right arrow and go down to select "automaticall connect to this network".
Press spacebar to put an X there then press F10 to save
it.

I then rebooted the machine.
After logging in, I went to the second console
and typed:
wicd-curses

At this point your network is selected an a
new connection is made.

I left the second console in the wicd page and
went back to console 1 for the rest of my
business.

After some time I deliberately pulled the antenna on
the network card to bring the connectio down. A
ping to the router confirmed there was no network
connection. I connected the antenna back up. In a
few seconds the connection was restored.

[root]

It isn't necessary to keep wicd-curses running.

>
> After some time I deliberately pulled the antenna on
> the network card to bring the connectio down. A
> ping to the router confirmed there was no network
> connection. I connected the antenna back up. In a
> few seconds the connection was restored.
>

I have been continuing experiments. I find that wicd
can maintain a connection if the dropout lasts for
5 seconds or less. I don't think this is a fix for
my problem after all.

[Ralph Spitzner]

root wrote:
[...]

> I have been continuing experiments. I find that wicd
> can maintain a connection if the dropout lasts for
> 5 seconds or less. I don't think this is a fix for
> my problem after all.
>

Just out of curiosity, is there any Bluetooth device
in either the vicinity of either the Ap or the client
trying to communicate ?
(This is what is giving me headaches over here...
[Bluetooth headset + wifi breaks both with my shitty AP)

-rasp

[Jim Diamond]

As well as microwave oven or (some) cordless phones.

Jim

[root]

No bluetooth in these systems.

[root]

Lots of cordless phones and a microwave oven. Thanks for
the tip.

[Justin]

Can you set your router to use 40Mhz channels rather than the normal 20?
I have a Buffalo AirStation 1750 dual band router. When my "el cheapo"
DECT 6.0 phone rang I would lose connectivity for a bit and then it would
come back. Since I switched to the 40Mhz wide channels it seems to be OK.

Also, have you tried switching to 5Ghz? Thats why I got the dual band
version, the 5Ghz is supposedly better for streaming and transferring
files, and it is a less crowded spectrum, but the indoor range is less
than 2Ghz. So I use both.

Strangely, when I had my Apple Airport Extreme it was not affected by the
phone.

[Martha Adams]

Two possibilities occur to me:

1) maybe you have a defective transmitter, causing the apparently
variable signal strength?

2) is this how your system responds to *interference*? And the
apparently variable signal strength arises from your system trying to
deal with the interference?

Titeotwawki -- Martha Adams [Thr 2013 May 16]

[root]

Justin <justinthe...@hatespam.edu> wrote:
>
> Can you set your router to use 40Mhz channels rather than the normal 20?
> I have a Buffalo AirStation 1750 dual band router. When my "el cheapo"
> DECT 6.0 phone rang I would lose connectivity for a bit and then it would
> come back. Since I switched to the 40Mhz wide channels it seems to be OK.

I can, and just did, switch to a 40MHz channel width. I'll give it a try.

>
> Also, have you tried switching to 5Ghz? Thats why I got the dual band
> version, the 5Ghz is supposedly better for streaming and transferring
> files, and it is a less crowded spectrum, but the indoor range is less
> than 2Ghz. So I use both.

I don't have a dual band router so that isn't an option for me.

>
> Strangely, when I had my Apple Airport Extreme it was not affected by the
> phone.

Thanks for responding.

[root]

Martha Adams <mh...@verizon.net> wrote:
> Two possibilities occur to me:
>
> 1) maybe you have a defective transmitter, causing the apparently
> variable signal strength?

I started to look into this problem because a friend's system was
dropping out. He uses AT&T U-verse system. I then set up a system
of mine to check my long term wireless connectivity. It is
possible that my friend and I both have transmitter problems.

In the case of my friend's system, his computer is within the
same room as his gateway, separated by about 8 feet. He just
doesn't want an ethernet cable running across the floor.

>
> 2) is this how your system responds to *interference*? And the
> apparently variable signal strength arises from your system trying to
> deal with the interference?

I think that is very likely. Also, my neighbor's Netgear router puts
out a stronger signal than mine. The system I set up to look into
the problem has a computer connected to my router two walls away
(there are two walls between the computer and the router). The
neighbor's router is also two walls away from my computer and
the distance to the neighbor's router is less.

>
> Titeotwawki -- Martha Adams [Thr 2013 May 16]
>

If it really is the end then I shouldn't bother with
my connectivity problems.

Thanks for responding.

[Tralfaz]

On Tue, 14 May 2013 14:08:51 +0000, root wrote:

I addressed this problem by going back to a wired connection. Screw if
the cat-6 cable looks bad...at least I can stay connected for more than 5
hours and don't sometimes get locked out so tight from the wireless
connection garbage that I have to hard reboot my system.

This problem happened with two different routers (an Linksys-E2500 and an
TPLINK-WR841N), both 'supported' by linux. It just got to be too much of
a PITA to mess with all the time. I don't blame anyone, it's just the way
it is until more devs jump into the 'wireless' pond to help out those who
are already there is all.