bit more info on the airmax protocol fro ubiquiti: Yes AirMax is the TDMA/Polling aspect of the software/hardware. This can be shut off. The backoff rules of the 802.11 protocol still apply to a certain extent (only from outside sources - inside the Ap/Client network they all have different time slots so they avoid collisions and hidden nodes all together.) So the polling doesnt take away the CSMA backoff mechanism of 802.11x from other noise sources....
________________________________ From: wireless-boun...@wispa.org on behalf of Gino Villarini Sent: Tue 8/18/2009 8:08 PM To: WISPA General List Subject: RE: [WISPA] Bullet M5 HP Jason Im sorry but i find some stated facts very difficult to believe. the 25db vs 3db snr ratio is based on the fact that canopy can perform as expected with just 3db over noise. MIMO based gear needs about 25 db snr ratio on both polarities in order to achieve good performence on 64qam and 2 chains. So if your noise floor is -80, youll need a -55 signal to get the high performance. I guessing hte nano / loco units would be good for really close clients, rocket dish for all others Gino ________________________________ From: wireless-boun...@wispa.org on behalf of Jayson Baker Sent: Tue 8/18/2009 7:44 PM To: WISPA General List Subject: Re: [WISPA] Bullet M5 HP MIMO (especially dual-pol) gets you much better performance. Cell phone companies have been doing this for years and years. You're 3dB vs 25dB comment is misleading. UBNT may need a received level of -70dBm to achieve higher speeds... but, so does a Canopy. You can't expect to achieve anything on a Canopy with, say, a -97dBm signal. Furthermore, UBNT will actually link around -95dBm and work, albeit slow. Canopy will say "SCANNING" We have tested these products, and have networks deployed both here in the states and in Costa Rica. You wouldn't think it, but Costa Rica has waaaaaaay more noise than we do here. The government uses 2.4 and 5GHz for random things, people have way overamp'ed equipment, there are a ton of little WISP's, etc. Canopy down there performs as expected... a couple mbps up, a couple mbps down. UBNT MIMO blows it away, especially with AirMax and in a noisy environment. When testing the MIMO you can't just run a single stream, they work best with many streams. We have seen about 130Mbps on a full-duplex on a deployed link, around 15 miles, in a noisy environment. With the PtMP equipment, we see similar results. With the older non-N non-MIMO equipment, we have seen up to 100+ subs on a single PowerStation AP, all getting at least 12Mbps/6Mbps, and latency always under 10ms. I get it, it's a Motorola list. We're on here because we use some of that too. Not much, anymore, because there are much better products out there. I'm sure this will start a flame war, as talk of anything other than Canopy always does, and I don't really care. The equipment is cheap enough, if you want to see it for yourself buy some and put it in. When you see it works as well as we've seen, you, too, can offer your subs 12Mbps for $25/mo and make killer profits. Our ROI on a new install is 1 Day. We make money the day it's installed. And it just works, we never have customers calling to complain. Cheers! On Tue, Aug 18, 2009 at 5:07 PM, Tom DeReggi <wirelessn...@rapiddsl.net>wrote: > Yeah, but its misleading garbage specs. > > Mimo adds very little in noisy environments, where double size channels and > both polarities can't be both used based on spectrum availabilty, not to > mention specifying gross speed instead of actual speeds. > > I'm not saying the Ubiquiti isn't a really nice needed product, I'm just > saying, in real world use, I'm not certain its faster than Motorola PtMP, > including advantage series. (per Mhz wide channel efficiency). Don't forget > the 3b SNR required by canopy and the 25db snr required by Ubiquiti for > high > modulations, which is rarely acheived in PtMP. Remember, a flaky > packetlossy link is going to bring TCP down to its knees in throuhgput > reduction. > > The most exciting thing about teh new product is its inferred that there > might be a low cost dual pol sector antenna available now? > > Tom DeReggi > RapidDSL & Wireless, Inc > IntAirNet- Fixed Wireless Broadband > > > ----- Original Message ----- > From: "Paul Hendry" <paul.hen...@skyline-networks.com> > To: "wireless" <wireless@wispa.org> > Sent: Tuesday, August 18, 2009 11:59 AM > Subject: Re: [WISPA] Bullet M5 HP > > > > Anyone had a chance to fully test any of Ubiquiti's claims like 150+mbps > > "real" throughput and 300+ subscribers per AP? Much more impressive > > numbers than Canopy. > > > > > > > > Matt wrote: > >>> Ubiquity has introduced their new product lines, at www.ubnt.com. > >>> Looking to take Canopy on. > >>> > >> > >> Anything like GPS sync for frequency reuse? > >> > >> Matt > >> > >> > >> > -------------------------------------------------------------------------------- > >> WISPA Wants You! Join today! > >> http://signup.wispa.org/ > >> > -------------------------------------------------------------------------------- > >> > >> WISPA Wireless List: wireless@wispa.org > >> > >> Subscribe/Unsubscribe: > >> http://lists.wispa.org/mailman/listinfo/wireless > >> > >> Archives: http://lists.wispa.org/pipermail/wireless/ > >> > > > > > > > -------------------------------------------------------------------------------- > > WISPA Wants You! 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