Charles,
Thanks for the links.
PS. I understand your points. (You can't
give it all away :-).
Tom DeReggi RapidDSL & Wireless, Inc IntAirNet- Fixed Wireless
Broadband
----- Original Message -----
Sent: Monday, June 26, 2006 10:55
AM
Subject: RE: [WISPA] frame size and fps -
was OT: about 70Mbps for under $ 6K
>You mention MadWifi driver has three
adaptive modulation methods. Do you know by any chance which one works best to
work with UDP traffic?
Given how different adaptive modulation methods are "optimized"
differently for different environments/situations/noise sources -- all I
can say is either pay me or RTFM <wink>
there is very good documentation on how the 2nd 2 methods are
"programmed" work
I
would also recommend that you to some refresher reading on
UDP
-Charles
P.S.
-- this isn't meant to be offensive, but this is research that a manufacturer
embarks on, as the average operator generally does not posess the requisite
level of knowledge to comprehend networking at this level -- the manufacturer
makes that 50-100% "value-add / markup / margin" for their work on this issue
so that the operator can "hopefully" just plug-in-pray =)
P.S.S. -- compared to the licensed / cellular wireless world, the vast
majority of license-exempt interference mitigation techniques (e.g., ARQ /
adaptive modulation / etc) aren't that great due to the fact that up until now
most manufacturers have limited their interference testing to gaussian "white
noise" conditions b/c the market is cheap
------------------------------------------- CWLab Technology
Architects http://www.cwlab.com
Charles,
We have often found that to get adequate
UDP performance without excessive packetloss, we need to turn off
Adaptive modulation on 802.11 radios (and hard set it).
Specifically, we have seen it with
Alvarion.
You mention MadWifi driver has three adaptive
modulation methods. Do you know by any chance which one works best to work
with UDP traffic?
This was one of our concerns putting 802.11
gear in place of our Trango gear that we typically prefer
because of its abilty to work as well with UDP as TCP.
Of course, if Trango had PtMP gear with an
External antenna CPE option, that also had non-beta ARQ firmware that didn't
lock up constantly, we would not be wasting time on this topic.
However they do not yet. So for these cases, we need to use
Atheros. It would be nice to find an adaptive modulation/ARQ version
that was UDP friendly. Can you offer any feedback on the
topic?
Tom DeReggi RapidDSL & Wireless, Inc IntAirNet- Fixed
Wireless Broadband
----- Original Message -----
Sent: Friday, June 23, 2006 11:56
AM
Subject: RE: [WISPA] frame size and
fps - was OT: about 70Mbps for under $ 6K
Hi Travis,
ARQ (which can mean anything) is standard for 802.11 --
(although changing / modifying ARQ mechanisms
requires HAL access)
A better illustrated example (which doesn't break any NDAs or
reveal any major IP) can be shown via adaptive
modulation
The MADWiFi driver alone gives 3 options for different adaptive
modulation schemes, onoe, amrr and sample, that can be chosen - some
are better than others http://madwifi.org/wiki/UserDocs/RateControl
-Charles
P.S. -- just like ARQ, not all adaptive modulation schemes are
created equal ---> in one case, we were able to improve a customer's
radio performance by approximately 20% through tweaks in the adaptive
modulation thresholds (in their case, they were being too conservative in
their backoff of Ethernet traffic and forgetting about their lower level
ARQ / FEC mechanisms)
------------------------------------------- CWLab Technology
Architects http://www.cwlab.com
Charles,
The other "advantage" I have been
told about Nstreme is it incorporates the equivalent of ARQ into the
protocol.
The other hidden advantage is it makes it impossible
for people to sniff the air for my signals unless they are using another
MT with Nstreme box. :)
Travis Microserv
Charles Wu
wrote:
Hi John,
Right or wrong, in the context of throughput efficiency, the documentation I
have seen regarding N-stream leads me to believe that frame concatenation is
the main method utilized by the protocol. Would you care to
expand/enlighten further (I am sure there are a lot of other inquisitive
types like me who like to know how the insides of their "black box" ticks =)
-Charles
P.S. -- I think you took my comments out of context -- I am by no means
implying that Mikrotik is a "bad" solution -- in fact, I personally happen
to like it a lot
-------------------------------------------
CWLab
Technology Architects
http://www.cwlab.com
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] On
Behalf Of John Tully
Sent: Thursday, June 22, 2006 1:30 AM
To: WISPA General List
Subject: RE: [WISPA] frame size and fps - was OT: about 70Mbps for under $
6K
Charles,
Usually I don't reply to 'opinions' like this. But, you have written
things that you know nothing about and acted as if you are an authority on
it.
Concerning our Atheros wireless support. We were one of the first
companies to ever support the Atheros for WISP systems in year 2000,
we supported the AR5000 5GHz only card. Before that we supported the
RadioLAN in 5GHz. We have written our drivers from the datasheet
up. If you take a close look, you will see allot of wireless
features that are unique -- such as dual Nstreme, wireless sniffer,
WPA2 with local keys... It is up too the customers to decide how
good they think the system is.
John
www.mikrotik.com
At 01:16 AM 6/22/2006, you wrote:
Hi Stephen,
Regarding performance gains, it is worth defining what is meant by that
term, as it can be vague and extremely misleading
For example, if my solution required a router, the fact that Mikrotik
had built in routing, while Alvarion did not, could be interpreted just
as much as being a "performance gain" as Alvarion being (according to
Tom D) more "interference resistant" than Mikrotik
In our context, I was referring to specifically the wireless context
>from a wireless standpoint, Mikrotik hasn't done anything IMO
extraordinary (at least they have HAL access though =) -- testing raw
aggregate throughput on Mikrotik point-to-point systems yields
generally similar throughput and packet per second numbers as "stock"
11a solutions -- now Nstream does offer some nifty features, but those
are more upper MAC related (e.g., polling to solve contention-based MAC
allocation)
This isn't meant to say that Mikrotik has a bad wireless driver,
rather, IMO, Mikrotik's value-add is more its integration of multiple
features (that many other products don't support)
On the other hand, others, like Alvarion, Trango and Star-OS (we
haven't finished testing Star-OS yet) -- have spent more effort diving
into the HAL and RF hardware portion (in the case more so for Alvarion
& Trango than Star-OS, which still utilizes cheap(er) off-the-shelf
mini-PCIs) to optimize Rf & throughput performance of their Atheros
based systems
On a 11a chipset, Trango gets ~40 Mb, Alvarion gets ~30 Mb (though this
may be changing w/ their new v4.0) and StarOS *supposedly* gets ~30 Mb
That said, then there's the question of user need -- am I willing to
sacrifice an additional 20-30% bandwidth efficiency and save additional
$$$$ in exchange for having a lot of other built-in nifty and useful
features?
-Charles
-------------------------------------------
CWLab
Technology Architects
<http://www.cwlab.com/> http://www.cwlab.com
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] On
Behalf Of Stephen Patrick
Sent: Tuesday, June 20, 2006 2:45 PM
To: 'WISPA General List'
Subject: RE: [WISPA] frame size and fps - was OT: about 70Mbps for
under $ 6K
Hi there,
Not detracting from this great debate, but I'd have to make some
Mikrotik comments at this point. We use their OS in our radios and the
"end product" we have on the market does out-perform several well-known
brands in terms of many parameters including throughput, stability and
RX sensitivity.
The "extras" (essentials for some customers) i.e. L3 features, wireless
extensions, security add huge value and reduce total network cost as
"extra boxes" suddenly vanish.
Shameless plug, we not only offer completed products with warranty but
training and full tech support (not the "e-mail us" variety: real
people to speak to, on-site presence when it matters, etc).
Of course Mikrotik "performance gains" might not apply if you were to
take a "DIY approach": performance can be terrible on the wrong
hardware, tech support absent and you wouldn't have vital (legally
required) certifications either.
But as a vendor having built and shipped wireless products that use
RouterOS and hearing the (cynical and wireless savvy) customer feedback
saying consistently "performance better than Brand X" even comparing a
simple L2 wireless bridge then I'd have to voice support for the OS.
Sure do compare with Star-OS and others; or a real DIY: build it from
bare hardware and FreeBSD/Linux with WiFi drivers or whatever... but as
this thread came from "vendor products" I thought it worth chipping in
- just my £0.01's worth.
Regards
Stephen
CableFree Solutions
www.cablefreesolutions.com
-----Original Message-----
From: Charles Wu [mailto:[EMAIL PROTECTED]]
Sent: 20 June 2006 20:15
To: 'WISPA General List'
Subject: RE: [WISPA] frame size and fps - was OT: about 70Mbps for
under $ 6K
Hi Tom,
Not to add another "chink" to your debate -- but it is worth noting
that Mikrotik is more of a "jack of all trades" solution (they do
routing, hotspot, etc) than a wireless solution
While they do an ok job w/ wireless, IMO, their strength is more the
convenience coming from the integration of multiple packages and its
flexibility rather than the performance of any single feature
If you're looking at purely a "wireless" solution (in this
"do-it-yourself"
genre) -- you need to include Star-OS / Ikarus in your evaluation (but
then,
documentation gets a bit sparse there...)
-Charles
-------------------------------------------
CWLab
Technology Architects
http://www.cwlab.com
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] On
Behalf Of Tom DeReggi
Sent: Monday, June 19, 2006 5:37 PM
To: WISPA General List
Subject: Re: [WISPA] frame size and fps - was OT: about 70Mbps for
under $ 6K
Paul,
Although many have reported very high speeds with Mikrotik. Our live
tests in noisy environments (wether accepted as accurate or not) showed
we were not able to get the peak speeds out of Mikrotik where we could
get them from
Alvarion. Our comparative tests were done with the Alvarion ver 3
firmware (not 4 yet). The Alvarion speeds that we got were right on the
numbers with the speeds test Alvarion tech support sent us. Actually
our tested speeds were a bit higher in some some cases. (Take note we
only got accurate speeds when we hard set modulation to optimal (picked
the best one for the
situation) modulation for testing).
I do not mean this as a negative comment on Mikrotik. Our competition
to Alvarion is NOT Trango, Trango does not yet have a 20 mbps product
for PtMP.
We look at our Trango as the best choice to tackle the worse noisy
environments (for us almost everywhere :-) Our competition for Alvarion
is actually Mikrotik.
Mikrotik probably has the single highest value from a feature cost
perspective. Why pay Alvarion price, when Mikrotik can do almost the
same thing at a fraction of the cost. Mikrotik has changed this market
and forced competing vendors to look at how to be more competitive.
Mikrotik is
doing what Trango did 4 years ago to drive the price down. (I'd argue
that Trango is still doing it also).
It will be real interesting to see how Alvarion performs side by side
to Mikrotik. The initial look show to me that Alvarion adds significant
features that make it the premium choice, possibly the leader in OFDM
today,
if price not part of the consideration. However, Mikrotik's flexibilty
and price clearly will keep them a major player for many WISPs.
Tom DeReggi
RapidDSL & Wireless, Inc
IntAirNet- Fixed Wireless Broadband
----- Original Message -----
From: "Paul Hendry" <[EMAIL PROTECTED]>
To: "'WISPA General List'" <wireless@wispa.org>
Sent: Friday, June 16, 2006 3:45 PM
Subject: RE: [WISPA] frame size and fps - was OT: about 70Mbps for
under $ 6K
Are these figures in the lab? I have seen similar with a
Mikrotik/N-Streme solution.
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]
On Behalf Of Patrick Leary
Sent: 16 June 2006 19:57
To: WISPA General List
Subject: RE: [WISPA] frame size and fps - was OT: about 70Mbps for
under $ 6K
So I have more data for you Matt I just received about what firmware
4.0 delivers in terms of frame sizes and what it can mean to the
business case. Remember, this is multipoint, not PtP. All Mbps
numbers are NET
throughput:
Frame size Upstream Mbps/FPS Downstream Mbps/FPS
64 32.18/47893 40.29/59952
128 34.7/29308 43.79/36982
256 37.68/17065 45.03/20392
512 38.41/9025 45.51/10693
1024 37.02/4432 44.82/5366
1280 38.93/3743 45.99/4422
1518 36.69/2982 44.63/3627
This is a dramatic improvement, first in terms of net throughput the
numbers are huge and I am pretty sure no other PMP system can get
close to them. But
the main accomplishment is a total leveling of capacity regardless of
the
frame size. This results in much higher predictability and ability to
capacity plan. This takes net throughput over 700% higher using small
64bit
frame than the previous version. Frankly it really is an exceptional
achievement that will enable operators to offer very high value services
even to large enterprise. With this version of BreezeACCESS VL an
operator
could sell an 8 voice lines/6Mbps of data to 20 enterprise customers
in a single sector with a 5:1 over subscription with a voice MOS of
4.0 or higher. And with a SOHO type service like 2 voice lines and
3Mbps of data you could have 160 customers PER sector at a 20:1 over
subscription. That will produce some exceptional ARPU.
Patrick Leary
AVP Marketing
Alvarion, Inc.
o: 650.314.2628
c: 760.580.0080
Vonage: 650.641.1243
-----Original Message-----
From: Matt Liotta [mailto:[EMAIL PROTECTED]]
Sent: Friday, June 16, 2006 6:47 AM
To: WISPA General List
Subject: Re: [WISPA] OT: about 70Mbps for under $6K
Patrick Leary wrote:
Matt, to further your comments that you see WISPs providing layer 2
transort
for carriers.
We have multiple CLECs and non-CLECs buying layer 2 transport from
us now. All are used to buy alternative access from fiber providers
and therefore fixed wireless was a naturally next step. Further,
almost all indicated they would have done it sooner, but the fixed
wireless companies they approached weren't willing to offer them
layer 2 transport.
How about VoIP? How many of you consider VoIP to be an important
part of your service future as a WISP? If so, how do you plan to
support since it cannot be done decently with the other popular 5GHz
solutions. That's not my opinion so much as the opinion of many
larger Trango and Motorola WISPs I have been talking to lately.
We are doing a significant amount of VoIP now. We have VoIP
customers running on top of both Trango and Canopy radios. Canopy is
a significantly better solution for VoIP since we can properly
prioritize voice with Canopy, while we cannot with Trango. We also
wholesale VoIP to other operators and help them --if they require
it-- with getting their network ready to support VoIP.
If a key goal of WISPs is growing ARPU, what are WISPs plans for
doing that with whatever your current technology permits?
I believe VoIP is the number one way to grow ARPU and the fact that
we bundle VoIP is why I believe we have one of the highest ARPUs in
the industry.
-Matt
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