Scott, For a 30 mile path in Florida with a 40dB fade margin the outage is predicted to be in excess of 20 hours. About 12 miles is the max I would use.
Mike 831-659-5618 -----Original Message----- From: wireless-boun...@wispa.org [mailto:wireless-boun...@wispa.org] On Behalf Of Scott Carullo Sent: Thursday, April 22, 2010 9:07 PM To: Travis Johnson; wireless@wispa.org Subject: Re: [WISPA] Couple more questions for the 11Ghz folks I guess my question would be whether the 6Ghz difference between 5gig and 11gig is as much different from 11gig to 18gig... Seams to me just guessing that 11gig and 18gig would act very differently for rain fade.... but then again I'm without any experience on either so I'm just probing for answers... Scott Carullo Brevard Wireless 321-205-1100 x102 ---------------------------------------- From: "Travis Johnson" <t...@ida.net> Sent: Thursday, April 22, 2010 11:58 PM To: sc...@brevardwireless.com, "WISPA General List" <wireless@wispa.org> Subject: Re: [WISPA] Couple more questions for the 11Ghz folks Hi, I assume you have had path analysis done already? Like by Trango or Dragonwave or whomever equipment you are considering for this project? What do their numbers show for availability? Honestly, a 30 mile link using 11ghz in Florida seems a little scary to me. I have some 18ghz links using a 4ft and 2ft dish going 32 miles and we experience rain-fade during our "heavy" rain storms... and considering we are technically in a desert climate, it makes me wonder about your links. (BTW, that's with my link running at the lowest modulation already, and they still drop out during the heavy storms). Travis Microserv Scott Carullo wrote: > Spending over 10K for a link (or anything for that matter) causes me to do > a bit more homework than usual when I'm dealing with something I am not > familiar with.... So more questions... Thanks ahead for your time I > appreciate any info provided. > > Looking for generic 11Ghz answers - not related specifically to any > manufacturer. > > Two links in question, one 20 miles and one 30 miles. 18db output 40.4 db > dish (4ft) 900ft tower to 300ft tower both instances 900ft tower in middle > with one link east one west. Calculations show just under 700 watts EIRP > > How much is the rain going to affect me... I have no experience with 11Ghz > and would really like a firm grasp on what happens to my link(s) when the > rain starts. I understand the Trango Apex which I'm looking at can > dynamically adjust speeds to account for some fade - exactly how much I'm > not sure. Any real world info would really help me at this point. I guess > I'm looking for good news :) but I need to hear the bad as well if it is > reality. > > Next question is for temp inversions. I have never had equipment higher > than about 350ft so the 900ft is a bit new for me. I'm assuming that the > angle different from going from 300ft to 300ft vs. 900ft to 300ft would be > a small portion of a degree difference so I'm not expecting anything > different here. Confirm this really won't make a difference for me as I > suspect... I'm not going over much water, just St. Johns river mostly > marsh but it does cause differences in temp above the water. Does 11Ghz > behave the same as 5Ghz for inversions? Worse, better? 5Ghz around here > sways a lot actually if you look at RSSI graphs. > > Anything else I might want to know, understand, be warned about etc? > Remember back to your first 10K + link :) That's me now... > > Scott Carullo > Brevard Wireless > 321-205-1100 x102 > > > > > ---------------------------------------------------------------------------- ---- > 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/
