108mbps products

I'm confused, in order to benefit from super G wireless products, do they
all need to be the same brand? and if not, how do you know certain products
from one brand are compatiable with ones from another?

 

"Super G" is a Atheros trademark for their 802.11g extensions (compression,
frame stuffing etc. etc). Super G Turbo is their 108M offering.

TI also have a 108M product (though I think they claim 100M), which I forget
the name of at the moment.

Broadcom call theirs "AfterBurner".

They are all incompatible, above plain 802.11g operation.

 

As mentioned by Gareth, 108mbs is not an adopted standard. Therefore
all 108mbs capable equipment is proprietry and will only work within
one manufacturer at full speed. However all devices also adhere to
the wireless G standard so they should be able to interconnect
properly at that level (i.e. 54mbs). I have no trouble connecting my
one device with a turbo card to my router and other clients without
turbo cards at 54mbs.

FWIW, for a home set up I'd use all the same brand anyway - regardless
of whether you are trying to use Super G or not. Whilst adhering to a
standard should ensure interoperability if you know you are going to
be connecting to the same router 99% of the time you'd be as well to
buy a client card from the same manufacturer as any compatability
issues are likely to have been more thoroughly explored.

 

I set up our home network with an Atheros based AP and Atheros based NICs.
All firmware and hardware supports "Super G" however I have chosen to leave
it turned off. Why? Because I know there is a person operating an 802.11b
AP just across the road from me. These 108Mbps standards operate by soaking
up more of the spectrum than they should.
As a direct result, there is significantly less bandwidth left around for
other wireless connections. If I were to enable "Super G" and start
shifting big files around my network my neighbour's AP would be flooded off
air.
The 802.11G standard was limited to 54mbps for a good reason. Be sociable
and keep the proprietary stuff off.

 

Super G isn't neccessarily 108M, Super G Turbo *is*.

Super G is the Atheros extension dealing with frame stuffing, compression
and a few other things.

"than they should". What a bizarre way of looking at it.

No it wouldn't, there would just be more collisions in whatever channel he
used - and there's a number of channels which he could use which would not
be affected by Atheros' Super G Turbo (which uses a fixed base channel of
6).

And in Dynamic Turbo mode (the only mode Atheros allow for use with XR),
Atheros will step down to 54M when it needs to.

 

That isn't true. The standard channels available for use are 1, 6 and 11.
These are allocated so that there is as little overlap between APs on
different channels as possible. The Super G and other protocls fix to the
middle channel and bleed into the outer channels. They effectively take
over 1, 6 and 11 all at once so that they have more bandwidth available to
use.
When I was looking into this I read up several tests which confirmed this.
They also confirmed that Turbo mode does not relinquish the spectrum when
other APs are around effectively flooding them off the air.

I confirmed this because I have turbo turned on at first. It was only when
I started playing around and turned it off temporarily that my neighbours
AP showed up. Apparently he though someone had been trying to hack his
network because he had all sorts of troubles whilst I had turbo enabled.

 

That explains why my existing 2 AP 802.11b network started having problems
when I was testing a Dlink 802.11g turbo (108Mb/s) AP.

Do multiple 108Mb/s APs play nicely together, assuming the same brand
and network, or do they also "flood" each other off the air?

Cheers,

Mark.

 

1-13 in this country / most ETSI countries. They overlap each other
(being wider than the separation between their centre frequencies). 1
doesn't overlap 6 which is where the 1,6 11 comes from (US based)

1, 7, 13 would be better in the UK.

http://www.theregister.co.uk/2004/03/17/atheros_updates_wifi_speed_booster/
describes a software mod to make "Super G" less hassle for neighbours,
it says they use channels 5 and 6 bonded but a competitor alleges they
bleed into wider frequencies that they should.

Certain chipsets (Broadcom) seem less tolerant of this type of
"enhancement".

The Atheros Super G white paper
http://www.atheros.com/pt/atheros_superg_whitepaper.pdf confirms it
uses two channels. Adding channel 5 to a unit operating on 6 will
overlap to some extent with 1 (by design) although Atheros claim to
have sharpened the cut off.

"Dynamic turbo" is supposed to disengage itself if it detects adjacent
networks.

Phil

 

what channels were they set to ?

Phil

 

According to iwconfig.... 2.462GHz, i.e. channel 11.

Cheers,

Mark.

 

all of them were on the same channel ?

 

The existing two 802.11b APs on the same channel (11) and the new 802.11g
(Dlink 108Mb/s) on channel 6 as I (think I) mentioned before.

The two 802.11b APs on channel 11 have been working well for around a
year with my laptop roaming between them smoothly as I move it around
the house.

Cheers,

Mark.

 

That may be what is allocated but most equipment is manufactured elsewhere.
All the APs I've used recently just have 1, 6 and 11.

<snip>
It wasn't just "a competitor". At the time I read a full independant
analysis showing spectral analysis with external hardware. A single normal
singal on channel 1 does actually bleed into 6 ever so slightly, but not
enough to make a difference.
The frequencies that SuperG used did bleed into channels 1 and 11 enough to
make a difference and the dynamic mode didn't give way to any of the other
non atheros based APs they tested.

I wish I still had the link but I'm not arsed about arguing enough to go
find it again.