Right... N relies on MIMO... so antenna diversity is important. In an indoor application this AP would have six small Omni antennas on it... just inches apart from each other. I don't think the exact placement of the antennas is important, as long as the patterns overlap. I've never seen anything specifying the distances of antennas... but if someone knows that would be great.
Either way, a dual-band antenna would cut it from six sectors to three... and not lose any of the benefits. Might not be cost effective, but I want to explore that. I'd also hope that there would be an antenna out there that already has the antenna diversity setup inside the antenna by having three elements pointing the correct directions. I wouldn't think noise would be that big of an issue at the antenna since they will all be broadcasting on the same frequency anyways. As for what he is trying to accomplish... I wish I knew. His application does not require 802.11n speeds, it could require the MIMO near and non-los properties... I think he wants 802.11n because it's the next thing. Just like I don't think he should be using Cisco... but no IT guy has ever been fired for deploying Cisco right :-) Daniel White 3-dB Networks http://www.3dbnetworks.com >-----Original Message----- >From: wireless-boun...@wispa.org [mailto:wireless-boun...@wispa.org] On >Behalf Of Marlon K. Schafer >Sent: Tuesday, February 24, 2009 8:34 AM >To: WISPA General List >Subject: Re: [WISPA] Dual-band Sector Antennas/Multiple Input Sector >Antennas > >I think the whole idea behind N is antenna diversity Daniel. > >Using less antennas means he'll get little or no benefit from the >system. >Might as well just run with a standard b/g system. > >I think antenna placement will also be critical for n. I could be >totally >wrong here, but my guess is that there are specific distances between >antennas that are part of the magic of n. > >What's he hoping to accomplish? > >Better NLOS, better nLOS, better speed? > >laters, >marlon > >----- Original Message ----- >From: "3-dB Networks" <wi...@3-db.net> >To: "'WISPA General List'" <wireless@wispa.org> >Sent: Tuesday, February 24, 2009 6:43 AM >Subject: [WISPA] Dual-band Sector Antennas/Multiple Input Sector >Antennas > > >> I'm helping someone design an antenna system to utilize the MIMO >> properties >> in 802.11n outdoors. The Cisco box he wants to connect to has three >5GHz >> and three 2.4GHz outputs. I'd rather avoid deploying six sector >antennas >> (only need to cover about 120 degrees. so I figured three 90degree >sectors >> ought to do it) so would like recommendations on : >> >> >> >> - Good dual-band 2.4GHz/5GHz antenna >> >> - Good Sector antenna that has multiple inputs on the same >band, >> same polarity (not sure if such a beast exists, but doesn't hurt >asking!). >> >> >> >> V-pol is preferred, as the clients will have V-pol omnis. >> >> >> >> Any help is really appreciated. Thanks! >> >> >> >> Daniel White >> >> 3-dB Networks >> >> http://www.3dbnetworks.com >> >> >> >> >> >> ---------------------------------------------------------------------- >---------- >> 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! 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! 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/
