Any reason to provide 11.b as a fallback?

I have an environment with an 11.g router, some 11.g clients and an
11.n client (connecting to the router via 11.g).

As there are no 11.b clients in the foreseeable future, I'm going to
deactivate the 11.b support on the router. (Currently running in
'Mixed' mode.)

I'm wondering if there is any benefit, potential detriment to doing
this, other than eliminating access to a 11.b client who might 'drop
by'.


TBerk

On Wed, 25 Jun 2008 08:48:45 -0700 (PDT), TBerk
<(E-Mail Removed)> wrote:

>I have an environment with an 11.g router, some 11.g clients and an
>11.n client (connecting to the router via 11.g).
>
>As there are no 11.b clients in the foreseeable future, I'm going to
>deactivate the 11.b support on the router. (Currently running in
>'Mixed' mode.)
>
>I'm wondering if there is any benefit, potential detriment to doing
>this, other than eliminating access to a 11.b client who might 'drop
>by'.

No. I suggest you disable 802.11b compatibility. That will allow
both the 802.11g and the 802.11n traffic to run at full speed. Details
if you want them.

--
Jeff Liebermann (E-Mail Removed)
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Jeff Liebermann wrote:

> On Wed, 25 Jun 2008 08:48:45 -0700 (PDT), TBerk
> <(E-Mail Removed)> wrote:
>
>
>>I have an environment with an 11.g router, some 11.g clients and an
>>11.n client (connecting to the router via 11.g).
>>
>>As there are no 11.b clients in the foreseeable future, I'm going to
>>deactivate the 11.b support on the router. (Currently running in
>>'Mixed' mode.)
>>
>>I'm wondering if there is any benefit, potential detriment to doing
>>this, other than eliminating access to a 11.b client who might 'drop
>>by'.
>
>
> No. I suggest you disable 802.11b compatibility. That will allow
> both the 802.11g and the 802.11n traffic to run at full speed. Details
> if you want them.
>

I would like to lobby for 802.11b support at all public access points;
add an 11b-only WAP to avoid degrading g/n performance. In some parts
of the country/world folks have 'mature' devices limited by O/S and
hardware to 802.11b and a hotspot operator stands to gain by being
agnostic on access method.

Michael

> In some parts
> of the country/world folks have 'mature' devices limited by O/S and
> hardware to 802.11b and a hotspot operator stands to gain by being
> agnostic on access method.

Frankly, if they're too cheap to replace the devices then they're unlikely
to fit in the scheme providing the wifi service. Why should a provider
burden their desireable customers (or their target advertising market) with
the slower, interferring traffic on the trailing edge crowd? This might
seem rude but it's harsh reality.

On Wed, 25 Jun 2008 14:16:56 -0500, msg <msg@_cybertheque.org_> wrote:

>I would like to lobby for 802.11b support at all public access points;

On the other foot, I would propose a nation ban on 802.11b devices as
an ecological measure in order to preserve rapidly diminishing air
time. 802.11b is so slow, that it hogs LOTS of air time, thus
preventing other users from communicating. It's very roughly
proportional to the connection frequency. For example, 1Mbit/sec data
hogs about 50 times the air time, so send the same amound of data, as
54Mbits/sec.

>add an 11b-only WAP to avoid degrading g/n performance.

The mere presence of 802.11b devices causes a degredation in available
bandwidth. Never mind that 802.11b sends *ALL* management packets at
the slowest 1Mbit/sec speed (for compatibility). 802.11g uses
9Mbits/sec.

>In some parts
>of the country/world folks have 'mature' devices limited by O/S and
>hardware to 802.11b and a hotspot operator stands to gain by being
>agnostic on access method.

Huh? I don't understand. What part of the world are you talking
about and what is the difference between "mature" device and an
obsolete piece of junk?

>Michael

--
# Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
# 831-336-2558 (E-Mail Removed)
# http://802.11junk.com (E-Mail Removed)
# http://www.LearnByDestroying.com AE6KS

On Fri, 27 Jun 2008 22:10:08 -0700, Jeff Liebermann <(E-Mail Removed)>
wrote:

>The mere presence of 802.11b devices causes a degredation in available
>bandwidth. Never mind that 802.11b sends *ALL* management packets at
>the slowest 1Mbit/sec speed (for compatibility). 802.11g uses
>9Mbits/sec.

Ooops. That should be 6Mbits/sec.

--
Jeff Liebermann (E-Mail Removed)
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Jeff Liebermann wrote:
> On Wed, 25 Jun 2008 14:16:56 -0500, msg <msg@_cybertheque.org_> wrote:
>
>
>>I would like to lobby for 802.11b support at all public access points;
>
>
> On the other foot, I would propose a nation ban on 802.11b devices as
> an ecological measure in order to preserve rapidly diminishing air
> time.

Well, perhaps this is a regional issue; in my area the spectrum is quite
underutilized and I am thankful that all known public access points
here do 11b. I would also suggest that much contemporary envionmental
action is counterproductive to human welfare.

<snip>

>
>>In some parts
>>of the country/world folks have 'mature' devices limited by O/S and
>>hardware to 802.11b and a hotspot operator stands to gain by being
>>agnostic on access method.
>
>
> Huh? I don't understand. What part of the world are you talking
> about and what is the difference between "mature" device and an
> obsolete piece of junk?
Harumph, nice to have money huh?

I am just now getting into H/PC (WinCE 2.11) on a Fujitsu Pencentra 130
and I appreciate its large screen format, complete set of standard
ports and connectors and manageable form factor. I don't really see
an equivalent product in newer technology and certainly not one that
I can use in the field for my intended applications. I may even
try NetBSD on the device if developing in CE isn't ultimately practical.
For now the best I can do for wifi is 11b using Rangelan/Openair/HomeRF
on it but it is servicable and very useful.

Michael

On Sat, 28 Jun 2008 16:16:18 -0500, msg <msg@_cybertheque.org_> wrote:

>> On the other foot, I would propose a nation ban on 802.11b devices as
>> an ecological measure in order to preserve rapidly diminishing air
>> time.
>
>Well, perhaps this is a regional issue; in my area the spectrum is quite
>underutilized and I am thankful that all known public access points
>here do 11b.

It varies. At home, I can see 5 access points (including the ones
that hide their SSID). I'm protected by the forest. However, at my
office, I can see about 25 access points without even trying, and
perhaps about 50 if I go outside and wave the laptop around. My 12
mile commute typically shows 150 or more access points with
Netstumbler and somewhat more with Kismet. The surest sign of success
is pollution and I guess Wi-Fi is successful.

>I would also suggest that much contemporary envionmental
>action is counterproductive to human welfare.

Yep. Much environment legislation oddly resembled redistributing the
wealth or the expense. Much ecological action seems to be based on
magic, alchemy, or junk science. Remind me to unload my standard rant
on how lead recycling was codified and handled.

>> Huh? I don't understand. What part of the world are you talking
>> about and what is the difference between "mature" device and an
>> obsolete piece of junk?

>Harumph, nice to have money huh?

Damn right it is. I worked hard for it, busted my ass, saved my
pennies, and took risks. So now I'm fairly comfortable. However, I
don't go out and buy the latest hardware just because someone declares
it obsolete. My pile of antique (1970's) test equipment should
indicate that I'm not buying new hardware.

However, that has nothing to do with my question. You said:

>>>In some parts
>>>of the country/world folks have 'mature' devices limited by O/S and
>>>hardware to 802.11b and a hotspot operator stands to gain by being
>>>agnostic on access method.

and I don't understand what you're complaining about. Making obsolete
technology mandatory is only effective if the obsolete industry has
something to gain by selling the same old junk. That happened between
about 1950 and 1990 in the avionics business, where the FAA made it
cost prohibitive for new technologies to be introduced. Lots of other
RF related industries have had similar problems with the FCC. However,
the average hot spot operator would just love to throw out the Wi-Fi
junk and just sell overpriced coffee and munchies. He doesn't care
what technology is being used, does not have a trade group lobbying
for the rights of hot spot operators, and is not even interested in
industry politics.

So, where on this planet, is there such a place where hot spot
operators stand to gain, lose, or even care, whether you use 802.11b
or not? If I misinterpreted what you said, then please restate your
rant.

>I am just now getting into H/PC (WinCE 2.11) on a Fujitsu Pencentra 130

<http://www.precisiongps.com/Webpages/Handhelds/fujitsu_handheld.htm>
About $17 with shipping. Add battery $35 and charger $28 on eBay:
<http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=360063433549>

>and I appreciate its large screen format, complete set of standard
>ports and connectors and manageable form factor.

I gotta admit, it is a nice package.

Incidentally, I collect HP LED type calculators. At one time, I
advocated making RPN mandatory on new calculators as I didn't want to
learn how to use algebraic entry type calculators.

>I don't really see
>an equivalent product in newer technology and certainly not one that
>I can use in the field for my intended applications.

That's good logic for why you bought one, but insufficient to justify
mandatory 802.11b support at hot spots just to prevent premature
obsolescence.

>I may even
>try NetBSD on the device if developing in CE isn't ultimately practical.
>For now the best I can do for wifi is 11b using Rangelan/Openair/HomeRF
>on it but it is servicable and very useful.

Those are all frequency hopping technologies and are NOT 802.11b.
They're just 802.11. None of them will work with the common DSSS
(direct sequence spread spectrum) access points. If you drag it to a
hot spot, it won't work. Perhaps you meant to suggest that we make
FHSS (frequency hopping spread spectrum) also mandatory? Incidentally,
I think I may have some Proxim Rangelan access points, which might
work. I also have a Symbol PPT-4300 Pen PC with exactly the same
problem.

--
Jeff Liebermann (E-Mail Removed)
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Jeff Liebermann wrote:

<snip>
>>For now the best I can do for wifi is 11b using Rangelan/Openair/HomeRF
>>on it but it is servicable and very useful.
>
>
> Those are all frequency hopping technologies and are NOT 802.11b.
> They're just 802.11.

Inadvertently redacted in the above before I posted:

For now the best I can do for wifi is 11b using a few supported cards
like the Roamabout and Orinoco Hermes stuff and Rangelan...

I do maintain a HomeRF 2.0 FHSS access point on premises for those
devices that use it and find that its connections are far more tolerant
of interference (QRM) and multipath and also the power output is ~100mw
with published hacks to double it, and receiver sensitivity is
published at ~-85dbm.

Michael

On Sat, 28 Jun 2008 19:45:16 -0500, msg <msg@_cybertheque.org_> wrote:

>Jeff Liebermann wrote:
>
><snip>
>>>For now the best I can do for wifi is 11b using Rangelan/Openair/HomeRF
>>>on it but it is servicable and very useful.
>>
>>
>> Those are all frequency hopping technologies and are NOT 802.11b.
>> They're just 802.11.
>
>Inadvertently redacted in the above before I posted:
>
>For now the best I can do for wifi is 11b using a few supported cards
>like the Roamabout and Orinoco Hermes stuff and Rangelan...

Hair splitting: RangeLAN2 uses Proxim's OpenAir spec and is usually
frequency hopping. RangeLAN-DS is 802.11b compatible. Orinoco Hermes
is the chipset used in the original Wavelan, Orinoco Gold, Orinoco
Silver, Avaya, and Agere cards. When Proxim bought the product line,
they changed the chipset.

>I do maintain a HomeRF 2.0 FHSS access point on premises for those
>devices that use it and find that its connections are far more tolerant
>of interference (QRM) and multipath and also the power output is ~100mw
>with published hacks to double it, and receiver sensitivity is
>published at ~-85dbm.

I only have a little experience with HomeRF, but have had quite a bit
with Breezecom/Alvarion, Symbol, and Raylink frequency hoppers (FHSS).
Also Metricom/Ricochet was FHSS. You're absolutely correct about
interference tolerance. In my never humble opinion, FHSS is the right
answer for dense and interference infested systems. When FHSS and
DSSS collide, FHSS always gets through, with traffic just slowing
down. DSSS always gets trashed and traffic comes to a complete stop.

Plenty big politics was involved with the FCC decision to promote DSSS
over FHSS. HomeRF was a reaction to the frustration of some vendors
with IEEE politics during 802.11g development. In its infinite
wisdom, the FCC decided to allow it, but only at drastically reduced
tx power output. The logic was that since it was superior and capable
of trashing DSSS, a reduction in power should put it at equal footing
for coexistence.

FHSS is required to hop over the entire 83.5MHz bandwidth, while DSSS
only uses about 25Mhz. While many systems could easily coexist if
everyone used FHSS, only 3 can with DSSS.

The spec sheets will show that FHSS receivers have worse sensitivity
than DSSS. That's not due to anything inherent in the technology.
It's simply that current DSSS chips use current process technologies
(SiGe), while FHSS tend to be much older (Bipolar) which has a higher
NF (noise figure).

All this stuff was a common debate in the early daze of 802.11, but is
now only a historical footnote as DSSS has obviously won the FH versus
DS competition.


--
Jeff Liebermann (E-Mail Removed)
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558