Re: wifi interference advice

["Robert G. (Doc) Savage" <dsavage@peaknet.net>]

BobKat,

[On an unrelated note, please set your message client to make
fixed-length lines (~72 chars) so we can read your posts easier.]

I've been a WisperISP customer for almost five years, and I can
sympathize with your plight. If I can offer any encouraging words, it's
that MOST of the time their system works very well. I'll also be the
first to say that some of their technicians should NEVER be allowed
anywhere NEAR paying customers. There was one guy 2-3 years ago that I
complained bitterly about to the owner.

I too have heard the "interfering with my signal" excuse. For this to be
valid -- at my house anyway -- once the interference starts it should
never go away. In my experience, an occasional or intermittent reception
problem has always been fixed. I normally don't hear what restored
service, but I always get the distinct impression that WisperISP found
something in their equipment chain that wasn't quite right. If your
connection has ever worked the way it should, then stumbles with long
pings and high packet loss, it's been my experience that the problem is
somewhere in their system. On the other hand, recent ice storms have
caused serious reception problems for many customers. Fortunately they
were relatively short duration events.

Going back to your original question, what you're asking for is
information about networking Layers 1 & 2. WiFi connections like ours
are inherently point-to-point radio links, usually in the 900 MHz band.
WisperISP's tower hubs are typically omnidirectional antennas, while
your rooftop radio has a very directional antennal. The modulation is
digital, so there's a fine line between 'works' and 'doesn't work'. That
threshold is typically between -75dB and -80dB. Link power budgets are
simple to calculate: Tx power + Tx antenna gain - path loss (depends on
distance & freq) + Rx antenna gain. If this sum -- the signal level at
the receiver -- is above its minimum threshold, you've got a link.

Your rooftop radio actually contains some teriffic diagnostic and
troubleshooting tools. Depending on how you are actually connected at
Layer 3, you may be able to temporarily re-config your router and log
onto the web interface of your radio. There you can read the received
signal level in real time. There is also a lot of other good information
available from that web-based interface.

Needless to say, this is not the sort of thing that Joe-Common-User will
have the ability to set up or read intuitively. However, if you are a
good and patient customer and catch the right tech support person with
the time to walk you through the process, together you can build a lot
of trust and understanding.

I would encourage you to contact the owner, Nathan Stooke, at his office
and tell him about your situation. He's an extremely reasonable guy and
knows his equipment & system like the back of his hand.

Good luck...

--Doc


On Sat, 2009-01-31 at 02:22 -0800, Bobby Castleberry wrote:
> It's been a while but I'm back.  I hope everyone is doing well.  Does anyone
> know a good place to find information on lower level wireless networking
> problems?  I live out in the boonies so I have whisper as my ISP (only option
> short of a T1, I am seriously considering a T) and my connection is at times
> aweful.  It will be going along just fine with 40ms pings and good bandwidth
> to 5000ms pings and 40% packet loss.  We've been through all the usual junk
> (them blaming my linux firewall, swapping wireless bridges, swapping antenna,
> running new antenna cable) and now you can tell they just don't want to deal
> with me any more because the answer has become "someone is creating
> interference which is breaking up your signal, there is nothing we can do
> about that".  The tower is a field away with no line of site issues and we
> get very good signal when we get signal.  If anyone can offer some friendly
> advice or point me to a technical forum that would be awesome.
>   I've been browsing around www.wirelessforums.org but this isn't your run
> of the mill windows/linksys problem.  
> 
> Bobkat



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