802.11g oversaturation?

Is it possible with 802.11g to oversaturate an area with access
points? Conventional wisdom suggests that the more coverage the
better, but I'm seeing very unstable connections in a new wireless
deployment. At any given time, my wireless clients can see as many as
10 access points (out of about 40 in the building) of varying signal
strengths. The coverage is this dense to ensure no area drops below 32
Mb/s. Is there anything in the standard (or just in someone's
experience) that makes this density ill advised. Thanks for any
advice!

Only thing I can think of is if all are running on the same channel. You
may want to try setting different points to different channels.

<(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> Is it possible with 802.11g to oversaturate an area with access
> points? Conventional wisdom suggests that the more coverage the
> better, but I'm seeing very unstable connections in a new wireless
> deployment. At any given time, my wireless clients can see as many as
> 10 access points (out of about 40 in the building) of varying signal
> strengths. The coverage is this dense to ensure no area drops below 32
> Mb/s. Is there anything in the standard (or just in someone's
> experience) that makes this density ill advised. Thanks for any
> advice!

On Mon, 06 Sep 2004 21:51:39 GMT, "Bryan Martin"
<(E-Mail Removed)> wrote:

>Only thing I can think of is if all are running on the same channel. You
>may want to try setting different points to different channels.

They are all on auto for channel. When I see several access points,
though, some of them are on the same channel. If this is not allowed
by the standard, I'm surprised the auto setting on the access point
doesn't avoid sharing a channel with a neighboring access point.

Yes, you can have too many access points. 802.11b/g only supports three
non-overlapping networks within range of one another. The typical channel
choices are 1, 6, and 11 in the US and Canada. Any other choices North
American equipment will result in some overlap and therefore some
interference for APs within range of one another. If an AP can see more than
two others, there has to be some interference.

If every client can really see 10 access points, then the clients are
probably thrashing trying to decide which AP to associate with, and the APs
are probably stepping on one another.

<(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> Is it possible with 802.11g to oversaturate an area with access
> points? Conventional wisdom suggests that the more coverage the
> better, but I'm seeing very unstable connections in a new wireless
> deployment. At any given time, my wireless clients can see as many as
> 10 access points (out of about 40 in the building) of varying signal
> strengths. The coverage is this dense to ensure no area drops below 32
> Mb/s. Is there anything in the standard (or just in someone's
> experience) that makes this density ill advised. Thanks for any
> advice!

On Sun, 05 Sep 2004 18:02:34 -0500, (E-Mail Removed) wrote:

~ Is it possible with 802.11g to oversaturate an area with access
~ points? Conventional wisdom suggests that the more coverage the
~ better, but I'm seeing very unstable connections in a new wireless
~ deployment. At any given time, my wireless clients can see as many as
~ 10 access points (out of about 40 in the building) of varying signal
~ strengths. The coverage is this dense to ensure no area drops below 32
~ Mb/s. Is there anything in the standard (or just in someone's
~ experience) that makes this density ill advised. Thanks for any
~ advice!

Sounds like you need to crank your power way down on both your
APs and clients.

See
http://www.cisco.com/en/US/products/...0802a036a.html
for an example of the sort of approach you would want to
employ when installing a high density 2.4GHz network.

Aaron

(E-Mail Removed) wrote in news:3o6nj0dnnsdoq0h8877nc31flce3k9nqup@
4ax.com:

> Is it possible with 802.11g to oversaturate an area with access
> points?

Yes, multiple APs within the same range maybe using the same channel.

Just remember that there are only 3 "real" channels to use.



--
Lucas Tam ((E-Mail Removed))
Please delete "REMOVE" from the e-mail address when replying.
http://members.ebay.com/aboutme/coolspot18/

On Tue, 07 Sep 2004 19:53:08 GMT, Lucas Tam <(E-Mail Removed)>
wrote:

>(E-Mail Removed) wrote in news:3o6nj0dnnsdoq0h8877nc31flce3k9nqup@
>4ax.com:
>
>> Is it possible with 802.11g to oversaturate an area with access
>> points?
>
>Yes, multiple APs within the same range maybe using the same channel.
>
>Just remember that there are only 3 "real" channels to use.

Any idea why this never affected me when I was running 802.11b? I've
had AP saturation at least this dense, plus my understanding is that
802.11b has an even longer range. Is this channel clutter something
that is only rearing its head now with higher speed wireless. How does
one manage to maximize speed (directly proportional to signal
strength, which is inversely proportional to distance), maintain
coverage, and minimize interference -- all within a multistory
environment?

Intelligently deploying access points to ensure no overlap across
three floors when I have to watch for two types of lateral overlap,
vertical overlap, and several possible diagonal overlaps -- this is
like a puzzle on the SAT. I assumed the "auto" setting for the
channels would sort all this out between the 11 channels the AP uses,
but it sounds like the technology requires more hand holding than
802.11b to have even a chance of success.

Do I really need to play some 3-dimensional chess here placing access
points, or is there an easy out I'm missing? 801.11a, maybe? It has
more channels, right? And shorter range? That should minimize APs on
the same channel overlapping. Or is it just a more expensive option
replete with its own pitfalls?

(E-Mail Removed) wrote in news:02dsj0po75j2j7d1u3lfhjjam9nr0n9npa@
4ax.com:

> Any idea why this never affected me when I was running 802.11b?

Maybe 802.11b was too slow for you to notice the slow speeds?

> Is this channel clutter something
> that is only rearing its head now with higher speed wireless.

This problem has been around for a while. My old Orinoco 802.11b
hardware had diagrams detailing best practices in regards to deploy a
high density network.

> but it sounds like the technology requires more hand holding than
> 802.11b to have even a chance of success.

Well... this should of been done with 802.11b as well ; )

> Do I really need to play some 3-dimensional chess here placing access
> points, or is there an easy out I'm missing?

Yes. Or you can hire someone to do a wireless site survey (or do one
yourself if you have the software).\


> 801.11a, maybe? It has
> more channels, right? And shorter range? That should minimize APs on
> the same channel overlapping. Or is it just a more expensive option
> replete with its own pitfalls?

If you got 802.11a... you'll have a limited choice of hardware. Not to
mention, a lot of users probably won't have 802.11a compatible hardware
at all.

However. 802.11a does have 8 to 12 non-overlapping channels. But if you
have a lot of APs... you'll still need to watch overlap.


--
Lucas Tam ((E-Mail Removed))
Please delete "REMOVE" from the e-mail address when replying.
http://members.ebay.com/aboutme/coolspot18/

<(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> On Tue, 07 Sep 2004 19:53:08 GMT, Lucas Tam <(E-Mail Removed)>
> wrote:
>
> >(E-Mail Removed) wrote in news:3o6nj0dnnsdoq0h8877nc31flce3k9nqup@
> >4ax.com:
> >
> >> Is it possible with 802.11g to oversaturate an area with access
> >> points?
> >
> >Yes, multiple APs within the same range maybe using the same channel.
> >
> >Just remember that there are only 3 "real" channels to use.
>
> Any idea why this never affected me when I was running 802.11b? I've
> had AP saturation at least this dense, plus my understanding is that
> 802.11b has an even longer range. Is this channel clutter something
> that is only rearing its head now with higher speed wireless. How does
> one manage to maximize speed (directly proportional to signal
> strength, which is inversely proportional to distance), maintain
> coverage, and minimize interference -- all within a multistory
> environment?

802.11b and 802.11g use the same frequency band and have pretty much the
same range, and the same aborption characteristics in building materials.
The difference in your experience between "b" and "g" might be explained by
many vendor-specific differences: transmitter power, receiver sensitivity,
antenna design.

>
> Intelligently deploying access points to ensure no overlap across
> three floors when I have to watch for two types of lateral overlap,
> vertical overlap, and several possible diagonal overlaps -- this is
> like a puzzle on the SAT. I assumed the "auto" setting for the
> channels would sort all this out between the 11 channels the AP uses,
> but it sounds like the technology requires more hand holding than
> 802.11b to have even a chance of success.

It sounds like you should hire a professional to do a survey, unless you
feel confident that you can learn enough by reading website material and
books to do a good one yourself. A large wifi installation in a limited area
is usually not going to just work without planning.

>
> Do I really need to play some 3-dimensional chess here placing access
> points, or is there an easy out I'm missing? 801.11a, maybe? It has
> more channels, right? And shorter range? That should minimize APs on
> the same channel overlapping. Or is it just a more expensive option
> replete with its own pitfalls?
>

802.11a has a smaller range, so you *might* have to deploy more APs to
effectively cover your space. But it has more channels, so the overlap
problem is greatly reduced. No-one will be able to use it unless you supply
802.11a client cards and software to everybody.