Re: [WISPA] 18ghz links
Hi Travis, The 18, 23, and 24 (UL) GHz Dragonwave products do downshift to QPSK from QAM; their 11 GHz product does not. I believe that this shift is already figured into Dragonwave's uptime figures. Your 28 mile link sounds like a good bet to me, but you might want to analyze maximum rainfall over the last four years to the maximum historical record for 100 years. I'm sure Dragonwave would be happy to help you justify the purchase of another link. Do you have raw data / graphs you could share of the performance of your Dragonwave links? I'd like to see if I can find a correlation between historical rainfall data and changes in your signal levels Best, -- Dylan Oliver Primaverity, LLC -- WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/
RE: [WISPA] 18ghz links
Hi Travis, Just looking to venture into the world of 18GHz. We are looking at our first link to be about 17.5 miles and I'm wondering if you could give us more details on your 19 mile link (heights, dish size/db, throughput speeds, fade margin, etc.) Many thanks, Paul. -Original Message- From: Travis Johnson [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Sent: 06 March 2007 05:00 To: isp-wireless@isp-wireless.com; WISPA General List Subject: [WISPA] 18ghz links Hi, We have had several 18ghz links up and running for almost 4 years. Using many of the path calc programs, they show as much as 28 minutes per year of outage (due to multi-path and rain fade). Yet, during the entire last 4 years, we have never seen the signal change by more than 3-4db. We have over 30db of fade margin on these links... so, my question is, does 18ghz just die instantly (like 38ghz does) in a heavy rain storm? We have never had either of our 18ghz links go down (one is 7 miles and the other is 19 miles). I am wanting to try and do a 28 mile link, and I can do it with 20db of fade margin... so I am wondering if that will be enough, or if the path calcs will be correct and we will have as much as 20 hours of downtime per year? (99.7653% uptime). Any thoughts? Travis Microserv -- WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/ -- WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/
Re: [WISPA] 18ghz links
Hi, We are in a very dry climate (actually considered a desert climate). Going 19 miles, we are using 4ft high performance dishes with high power radios (+22db output) and we have 32db of fade margin. This link has never been down in 3+ years. Travis Microserv paul hendry wrote: Hi Travis, Just looking to venture into the world of 18GHz. We are looking at our first link to be about 17.5 miles and I'm wondering if you could give us more details on your 19 mile link (heights, dish size/db, throughput speeds, fade margin, etc.) Many thanks, Paul. -Original Message- From: Travis Johnson [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Sent: 06 March 2007 05:00 To: isp-wireless@isp-wireless.com; WISPA General List Subject: [WISPA] 18ghz links Hi, We have had several 18ghz links up and running for almost 4 years. Using many of the path calc programs, they show as much as 28 minutes per year of outage (due to multi-path and rain fade). Yet, during the entire last 4 years, we have never seen the signal change by more than 3-4db. We have over 30db of fade margin on these links... so, my question is, does 18ghz just die instantly (like 38ghz does) in a heavy rain storm? We have never had either of our 18ghz links go down (one is 7 miles and the other is 19 miles). I am wanting to try and do a 28 mile link, and I can do it with 20db of fade margin... so I am wondering if that will be enough, or if the path calcs will be correct and we will have as much as 20 hours of downtime per year? (99.7653% uptime). Any thoughts? Travis Microserv -- WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/
Re: [WISPA] 18ghz links
Are these Dragon Wave links? This is good news for the up-time you are seeing. Do you have much rain where you are? I am definitely more interested in this band now. What kind of speeds can a guy expect from links like this? How much do they cost? Thanks much, Scriv Travis Johnson wrote: Hi, We have had several 18ghz links up and running for almost 4 years. Using many of the path calc programs, they show as much as 28 minutes per year of outage (due to multi-path and rain fade). Yet, during the entire last 4 years, we have never seen the signal change by more than 3-4db. We have over 30db of fade margin on these links... so, my question is, does 18ghz just die instantly (like 38ghz does) in a heavy rain storm? We have never had either of our 18ghz links go down (one is 7 miles and the other is 19 miles). I am wanting to try and do a 28 mile link, and I can do it with 20db of fade margin... so I am wondering if that will be enough, or if the path calcs will be correct and we will have as much as 20 hours of downtime per year? (99.7653% uptime). Any thoughts? Travis Microserv -- WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/
Re: [WISPA] 18ghz links
Hi, The last three links we installed have been Dragonwave (two AirPair 50's and one AirPair 100). They provide full-duplex operation at whatever speed you buy (so the AirPair 50's will do 50Mbps x 50Mbps). I have been able to get 52Mbps across the 50's using the Mikrotik speed test program (TCP). Cost can vary depending on antenna size, but in the least expensive config you are around $16k with the FCC license. The previous two links were WitCom units. They were more like $25k (4 years ago), but have paid for themselves many times over. :) Travis Microserv John Scrivner wrote: Are these Dragon Wave links? This is good news for the up-time you are seeing. Do you have much rain where you are? I am definitely more interested in this band now. What kind of speeds can a guy expect from links like this? How much do they cost? Thanks much, Scriv Travis Johnson wrote: Hi, We have had several 18ghz links up and running for almost 4 years. Using many of the path calc programs, they show as much as 28 minutes per year of outage (due to multi-path and rain fade). Yet, during the entire last 4 years, we have never seen the signal change by more than 3-4db. We have over 30db of fade margin on these links... so, my question is, does 18ghz just die instantly (like 38ghz does) in a heavy rain storm? We have never had either of our 18ghz links go down (one is 7 miles and the other is 19 miles). I am wanting to try and do a 28 mile link, and I can do it with 20db of fade margin... so I am wondering if that will be enough, or if the path calcs will be correct and we will have as much as 20 hours of downtime per year? (99.7653% uptime). Any thoughts? Travis Microserv -- WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/
