Re: [WISPA] 900MHZ Farm GOS..Was: That black magic
John Deere did send me their channel plan. They are able to turn frequencies on and off. That said, I thought Iowa's RTK network was ran by the DOT and not the farmers. Maybe the receivers aren't compatible with the state's network. We aren't a big farm, but we're going to be using RTK this year. We've been using GPS in general for well over 10 years, probably 15. - Mike Hammett Intelligent Computing Solutions http://www.ics-il.com -- From: "Mike" Sent: Wednesday, February 24, 2010 12:34 PM To: "'WISPA General List'" Subject: Re: [WISPA] 900MHZ Farm GOS..Was: That black magic > I too would believe the systems are FCC certified. I have no details > other > than to say I avoid 900 MHz like the plague. > > They seem to use the entire band. They are appearing everywhere in my > area. > The repeaters or aggregators are atop poles, bins, grain legs. It is cool > technology (ever seen a huge combine turn itself around at the end of the > rows and start back the other way?) > > While they usually aren't on all the time, disking, planting, cultivating, > spraying, and combining times shoot holes in the usability. I have seen > some that are on whenever the machinery key is on. > > It's not the small farmers, but the big family and corporate farmers who > use > them, including some of my customers. > > Mike > > -Original Message- > From: wireless-boun...@wispa.org [mailto:wireless-boun...@wispa.org] On > Behalf Of Justin Wilson > Sent: Wednesday, February 24, 2010 11:00 AM > To: WISPA General List > Subject: [WISPA] 900MHZ Farm GOS..Was: That black magic > > Are the 900 MHZ systems the farm operations are using FCC Certified? > Anyone > have some details on them? I have been on towers where such systems exist. > Interested in any info others have on them. > > Justin > > -- > Justin Wilson > CCNA CCNT Mikrotik Advanced > http://j2sw.mtin.net/blog > ³My posts are my opinions.² > > > > From: David Hulsebus > Reply-To: WISPA General List > Date: Wed, 24 Feb 2010 11:50:08 -0500 > To: WISPA General List > Subject: Re: [WISPA] That black magic > > We see some of the same interference issues. It was actually much better > when all the cordless phones were 900, verses meters, farm operations, > etc... > > Yes it's NLOS, if I went up another 40 ft I would have LOS. With NLOS > we only have about 25 yards of trees to deal with 100 yards or so from > the house, but no dirt. He's 1.35 miles from the tower, the AP is 150 > above his GL. We do use a Cushcraft 906 antenna on his end and an Antel > 120 deg, 3 deg electrical down tilt on the tower that puts out 34.8 > EIRP. A filter we changed out a couple of years ago dropped our output a > bit more than a db. Now that the beans are gone, his signal stabilized > and improved from a fluctuating -75 to -83 back to a -70 > > This is an older CCU3100 WaveRider system that doesn't run OFDM, but > DSSS. I tried a panel antenna instead of the yagi and it improved the > fluctuation some, but didn't improve the signal like going up 10 ft did. > So I think you are correct that the changes in multipath from a little > wind and lots of hardened leafs and beans reflected the signal more than > when they had enough moisture to absorb more than reflect. > > Dave > > Mike wrote: >> 900 MHz doesn't work well around here. The farmers have deployed GPS >> navigation systems using those frequencies. >> >> Was the bean path you had NLOS? I'm curious what effects it had. I have >> seen a four foot change in elevation work like black magic. I think the >> beans get to blowing in the breeze and because there are hundreds of >> thousands of little hard points that randomly diffract the signal it > fades. >> I saw this on a knife edge diffraction path as well as a distant, path > where >> the CPE had to be mounted low to clear large branches of an oak tree 20 > feet >> overhead. The next field over was a bean field one year and caused fits > for >> a couple weeks, I believe because of the low angle. Is it that OFDM can >> survive in a multipath environment until the individually randomized > signals >> number in the thousands? >> >> Mike >> >> -Original Message- >> From: wireless-boun...@wispa.org [mailto:wireless-boun...@wispa.org] On >> Behalf Of David Hulsebus >> Sent: Tuesday, February 23, 2010 3:04 PM >> To: WISPA General List >> Subject: Re: [WISPA] That black magic >> >> Mike, Interesting you mentioned soy beans. I have a cust
Re: [WISPA] 900MHZ Farm GOS..Was: That black magic
One company I talked to that want try to co locate on one of the grain bins we are on confirmed their equipment was a "slow" bandwidth frequency hopper that used the entire band. Seemed they had no configuration options to set what frequencies used. It didn't provide lot of bandwidth but was a constant steady data stream. Told them I didn't think that would work on that close proximity unless they could avoid using certain frequencies that we used. /Eje Sent via BlackBerry from T-Mobile -Original Message- From: "Mike" Date: Wed, 24 Feb 2010 12:34:01 To: 'WISPA General List' Subject: Re: [WISPA] 900MHZ Farm GOS..Was: That black magic I too would believe the systems are FCC certified. I have no details other than to say I avoid 900 MHz like the plague. They seem to use the entire band. They are appearing everywhere in my area. The repeaters or aggregators are atop poles, bins, grain legs. It is cool technology (ever seen a huge combine turn itself around at the end of the rows and start back the other way?) While they usually aren't on all the time, disking, planting, cultivating, spraying, and combining times shoot holes in the usability. I have seen some that are on whenever the machinery key is on. It's not the small farmers, but the big family and corporate farmers who use them, including some of my customers. Mike -Original Message- From: wireless-boun...@wispa.org [mailto:wireless-boun...@wispa.org] On Behalf Of Justin Wilson Sent: Wednesday, February 24, 2010 11:00 AM To: WISPA General List Subject: [WISPA] 900MHZ Farm GOS..Was: That black magic Are the 900 MHZ systems the farm operations are using FCC Certified? Anyone have some details on them? I have been on towers where such systems exist. Interested in any info others have on them. Justin -- Justin Wilson CCNA CCNT Mikrotik Advanced http://j2sw.mtin.net/blog ³My posts are my opinions.² From: David Hulsebus Reply-To: WISPA General List Date: Wed, 24 Feb 2010 11:50:08 -0500 To: WISPA General List Subject: Re: [WISPA] That black magic We see some of the same interference issues. It was actually much better when all the cordless phones were 900, verses meters, farm operations, etc... Yes it's NLOS, if I went up another 40 ft I would have LOS. With NLOS we only have about 25 yards of trees to deal with 100 yards or so from the house, but no dirt. He's 1.35 miles from the tower, the AP is 150 above his GL. We do use a Cushcraft 906 antenna on his end and an Antel 120 deg, 3 deg electrical down tilt on the tower that puts out 34.8 EIRP. A filter we changed out a couple of years ago dropped our output a bit more than a db. Now that the beans are gone, his signal stabilized and improved from a fluctuating -75 to -83 back to a -70 This is an older CCU3100 WaveRider system that doesn't run OFDM, but DSSS. I tried a panel antenna instead of the yagi and it improved the fluctuation some, but didn't improve the signal like going up 10 ft did. So I think you are correct that the changes in multipath from a little wind and lots of hardened leafs and beans reflected the signal more than when they had enough moisture to absorb more than reflect. Dave Mike wrote: > 900 MHz doesn't work well around here. The farmers have deployed GPS > navigation systems using those frequencies. > > Was the bean path you had NLOS? I'm curious what effects it had. I have > seen a four foot change in elevation work like black magic. I think the > beans get to blowing in the breeze and because there are hundreds of > thousands of little hard points that randomly diffract the signal it fades. > I saw this on a knife edge diffraction path as well as a distant, path where > the CPE had to be mounted low to clear large branches of an oak tree 20 feet > overhead. The next field over was a bean field one year and caused fits for > a couple weeks, I believe because of the low angle. Is it that OFDM can > survive in a multipath environment until the individually randomized signals > number in the thousands? > > Mike > > -Original Message- > From: wireless-boun...@wispa.org [mailto:wireless-boun...@wispa.org] On > Behalf Of David Hulsebus > Sent: Tuesday, February 23, 2010 3:04 PM > To: WISPA General List > Subject: Re: [WISPA] That black magic > > Mike, Interesting you mentioned soy beans. I have a customer > (900-WaveRider) who was installed for 5 yrs next to a corn field. The > crop was replaced with soy beans this past year and a month before > harvest, as the beans dried out, we started having signal fluctuation > issues. We raised the antenna 10 ft and the problem went away. It was > their first issue in 5 yrs. > > Dave > > > > Mike wrote: > >> I need to do a reality check with those of you familiar with knife edge
Re: [WISPA] 900MHZ Farm GOS..Was: That black magic
I too would believe the systems are FCC certified. I have no details other than to say I avoid 900 MHz like the plague. They seem to use the entire band. They are appearing everywhere in my area. The repeaters or aggregators are atop poles, bins, grain legs. It is cool technology (ever seen a huge combine turn itself around at the end of the rows and start back the other way?) While they usually aren't on all the time, disking, planting, cultivating, spraying, and combining times shoot holes in the usability. I have seen some that are on whenever the machinery key is on. It's not the small farmers, but the big family and corporate farmers who use them, including some of my customers. Mike -Original Message- From: wireless-boun...@wispa.org [mailto:wireless-boun...@wispa.org] On Behalf Of Justin Wilson Sent: Wednesday, February 24, 2010 11:00 AM To: WISPA General List Subject: [WISPA] 900MHZ Farm GOS..Was: That black magic Are the 900 MHZ systems the farm operations are using FCC Certified? Anyone have some details on them? I have been on towers where such systems exist. Interested in any info others have on them. Justin -- Justin Wilson CCNA CCNT Mikrotik Advanced http://j2sw.mtin.net/blog ³My posts are my opinions.² From: David Hulsebus Reply-To: WISPA General List Date: Wed, 24 Feb 2010 11:50:08 -0500 To: WISPA General List Subject: Re: [WISPA] That black magic We see some of the same interference issues. It was actually much better when all the cordless phones were 900, verses meters, farm operations, etc... Yes it's NLOS, if I went up another 40 ft I would have LOS. With NLOS we only have about 25 yards of trees to deal with 100 yards or so from the house, but no dirt. He's 1.35 miles from the tower, the AP is 150 above his GL. We do use a Cushcraft 906 antenna on his end and an Antel 120 deg, 3 deg electrical down tilt on the tower that puts out 34.8 EIRP. A filter we changed out a couple of years ago dropped our output a bit more than a db. Now that the beans are gone, his signal stabilized and improved from a fluctuating -75 to -83 back to a -70 This is an older CCU3100 WaveRider system that doesn't run OFDM, but DSSS. I tried a panel antenna instead of the yagi and it improved the fluctuation some, but didn't improve the signal like going up 10 ft did. So I think you are correct that the changes in multipath from a little wind and lots of hardened leafs and beans reflected the signal more than when they had enough moisture to absorb more than reflect. Dave Mike wrote: > 900 MHz doesn't work well around here. The farmers have deployed GPS > navigation systems using those frequencies. > > Was the bean path you had NLOS? I'm curious what effects it had. I have > seen a four foot change in elevation work like black magic. I think the > beans get to blowing in the breeze and because there are hundreds of > thousands of little hard points that randomly diffract the signal it fades. > I saw this on a knife edge diffraction path as well as a distant, path where > the CPE had to be mounted low to clear large branches of an oak tree 20 feet > overhead. The next field over was a bean field one year and caused fits for > a couple weeks, I believe because of the low angle. Is it that OFDM can > survive in a multipath environment until the individually randomized signals > number in the thousands? > > Mike > > -Original Message- > From: wireless-boun...@wispa.org [mailto:wireless-boun...@wispa.org] On > Behalf Of David Hulsebus > Sent: Tuesday, February 23, 2010 3:04 PM > To: WISPA General List > Subject: Re: [WISPA] That black magic > > Mike, Interesting you mentioned soy beans. I have a customer > (900-WaveRider) who was installed for 5 yrs next to a corn field. The > crop was replaced with soy beans this past year and a month before > harvest, as the beans dried out, we started having signal fluctuation > issues. We raised the antenna 10 ft and the problem went away. It was > their first issue in 5 yrs. > > Dave > > > > Mike wrote: > >> I need to do a reality check with those of you familiar with knife edge >> diffraction as a propagation medium. First, I should paint the scene: >> >> >> >> I have a corporate farmer almost 16 miles away who is motivated. His >> options are satellite, dialup he currently uses, or us. >> >> >> >> A spectrum sweep of the property found absolutely no 2.4 signals. By in >> large, these rural areas are very quiet. >> >> >> >> There are no trees or obstructions in the near field or out quite a ways. >> However, there is a ridge almost half way between us. I am embedding an >> image of the path here created with alphimax.com path estimator. >> >>
Re: [WISPA] 900MHZ Farm GOS..Was: That black magic
I would assume that if John Deere, etc. are selling systems, they're FCC certified. John Deere is coming out with a 450 MHz product for challenging RF situations, but the 900 MHz will still be the default product. - Mike Hammett Intelligent Computing Solutions http://www.ics-il.com -- From: "Justin Wilson" Sent: Wednesday, February 24, 2010 10:59 AM To: "WISPA General List" Subject: [WISPA] 900MHZ Farm GOS..Was: That black magic > Are the 900 MHZ systems the farm operations are using FCC Certified? > Anyone > have some details on them? I have been on towers where such systems exist. > Interested in any info others have on them. > > Justin > > -- > Justin Wilson > CCNA CCNT Mikrotik Advanced > http://j2sw.mtin.net/blog > ³My posts are my opinions.² > > > > From: David Hulsebus > Reply-To: WISPA General List > Date: Wed, 24 Feb 2010 11:50:08 -0500 > To: WISPA General List > Subject: Re: [WISPA] That black magic > > We see some of the same interference issues. It was actually much better > when all the cordless phones were 900, verses meters, farm operations, > etc... > > Yes it's NLOS, if I went up another 40 ft I would have LOS. With NLOS > we only have about 25 yards of trees to deal with 100 yards or so from > the house, but no dirt. He's 1.35 miles from the tower, the AP is 150 > above his GL. We do use a Cushcraft 906 antenna on his end and an Antel > 120 deg, 3 deg electrical down tilt on the tower that puts out 34.8 > EIRP. A filter we changed out a couple of years ago dropped our output a > bit more than a db. Now that the beans are gone, his signal stabilized > and improved from a fluctuating -75 to -83 back to a -70 > > This is an older CCU3100 WaveRider system that doesn't run OFDM, but > DSSS. I tried a panel antenna instead of the yagi and it improved the > fluctuation some, but didn't improve the signal like going up 10 ft did. > So I think you are correct that the changes in multipath from a little > wind and lots of hardened leafs and beans reflected the signal more than > when they had enough moisture to absorb more than reflect. > > Dave > > Mike wrote: >> 900 MHz doesn't work well around here. The farmers have deployed GPS >> navigation systems using those frequencies. >> >> Was the bean path you had NLOS? I'm curious what effects it had. I have >> seen a four foot change in elevation work like black magic. I think the >> beans get to blowing in the breeze and because there are hundreds of >> thousands of little hard points that randomly diffract the signal it >> fades. >> I saw this on a knife edge diffraction path as well as a distant, path >> where >> the CPE had to be mounted low to clear large branches of an oak tree 20 >> feet >> overhead. The next field over was a bean field one year and caused fits >> for >> a couple weeks, I believe because of the low angle. Is it that OFDM can >> survive in a multipath environment until the individually randomized >> signals >> number in the thousands? >> >> Mike >> >> -Original Message- >> From: wireless-boun...@wispa.org [mailto:wireless-boun...@wispa.org] On >> Behalf Of David Hulsebus >> Sent: Tuesday, February 23, 2010 3:04 PM >> To: WISPA General List >> Subject: Re: [WISPA] That black magic >> >> Mike, Interesting you mentioned soy beans. I have a customer >> (900-WaveRider) who was installed for 5 yrs next to a corn field. The >> crop was replaced with soy beans this past year and a month before >> harvest, as the beans dried out, we started having signal fluctuation >> issues. We raised the antenna 10 ft and the problem went away. It was >> their first issue in 5 yrs. >> >> Dave >> >> >> >> Mike wrote: >> >>> I need to do a reality check with those of you familiar with knife edge >>> diffraction as a propagation medium. First, I should paint the scene: >>> >>> >>> >>> I have a corporate farmer almost 16 miles away who is motivated. His >>> options are satellite, dialup he currently uses, or us. >>> >>> >>> >>> A spectrum sweep of the property found absolutely no 2.4 signals. By in >>> large, these rural areas are very quiet. >>> >>> >>> >>> There are no trees or obstructions in the near field or out quite a >>> ways. >>> However, there is a ridge almost half way between us. I am embedding an >>> image of the path here created with alphimax.com p
[WISPA] 900MHZ Farm GOS..Was: That black magic
Are the 900 MHZ systems the farm operations are using FCC Certified? Anyone have some details on them? I have been on towers where such systems exist. Interested in any info others have on them. Justin -- Justin Wilson CCNA CCNT Mikrotik Advanced http://j2sw.mtin.net/blog ³My posts are my opinions.² From: David Hulsebus Reply-To: WISPA General List Date: Wed, 24 Feb 2010 11:50:08 -0500 To: WISPA General List Subject: Re: [WISPA] That black magic We see some of the same interference issues. It was actually much better when all the cordless phones were 900, verses meters, farm operations, etc... Yes it's NLOS, if I went up another 40 ft I would have LOS. With NLOS we only have about 25 yards of trees to deal with 100 yards or so from the house, but no dirt. He's 1.35 miles from the tower, the AP is 150 above his GL. We do use a Cushcraft 906 antenna on his end and an Antel 120 deg, 3 deg electrical down tilt on the tower that puts out 34.8 EIRP. A filter we changed out a couple of years ago dropped our output a bit more than a db. Now that the beans are gone, his signal stabilized and improved from a fluctuating -75 to -83 back to a -70 This is an older CCU3100 WaveRider system that doesn't run OFDM, but DSSS. I tried a panel antenna instead of the yagi and it improved the fluctuation some, but didn't improve the signal like going up 10 ft did. So I think you are correct that the changes in multipath from a little wind and lots of hardened leafs and beans reflected the signal more than when they had enough moisture to absorb more than reflect. Dave Mike wrote: > 900 MHz doesn't work well around here. The farmers have deployed GPS > navigation systems using those frequencies. > > Was the bean path you had NLOS? I'm curious what effects it had. I have > seen a four foot change in elevation work like black magic. I think the > beans get to blowing in the breeze and because there are hundreds of > thousands of little hard points that randomly diffract the signal it fades. > I saw this on a knife edge diffraction path as well as a distant, path where > the CPE had to be mounted low to clear large branches of an oak tree 20 feet > overhead. The next field over was a bean field one year and caused fits for > a couple weeks, I believe because of the low angle. Is it that OFDM can > survive in a multipath environment until the individually randomized signals > number in the thousands? > > Mike > > -Original Message- > From: wireless-boun...@wispa.org [mailto:wireless-boun...@wispa.org] On > Behalf Of David Hulsebus > Sent: Tuesday, February 23, 2010 3:04 PM > To: WISPA General List > Subject: Re: [WISPA] That black magic > > Mike, Interesting you mentioned soy beans. I have a customer > (900-WaveRider) who was installed for 5 yrs next to a corn field. The > crop was replaced with soy beans this past year and a month before > harvest, as the beans dried out, we started having signal fluctuation > issues. We raised the antenna 10 ft and the problem went away. It was > their first issue in 5 yrs. > > Dave > > > > Mike wrote: > >> I need to do a reality check with those of you familiar with knife edge >> diffraction as a propagation medium. First, I should paint the scene: >> >> >> >> I have a corporate farmer almost 16 miles away who is motivated. His >> options are satellite, dialup he currently uses, or us. >> >> >> >> A spectrum sweep of the property found absolutely no 2.4 signals. By in >> large, these rural areas are very quiet. >> >> >> >> There are no trees or obstructions in the near field or out quite a ways. >> However, there is a ridge almost half way between us. I am embedding an >> image of the path here created with alphimax.com path estimator. >> >> >> >> >> >> >> >> >> >> I have a test unit which is a 19 dB panel/radio with an AP fastened to the >> back. It lets me hand hold a test unit and see what it sees on a laptop. >> Standing on the ground on his property we got an ALMOST usable signal in a >> short test. He has a 35 foot TV tower next to the house on which we would >> install. >> >> >> >> Perhaps one would look at the path profile and common sense would dictate >> > it > >> won't work. However, I use knife edge diffraction successfully on a >> > handful > >> of installs. Besides, black magic sometimes trumps common sense. >> >> >> >> I have never used this technique where the ridge is close to mid point. >> > On > >> all others the ridge was closer to the user. All of them work except when >> tropospheric ducting enters into the equation, with one exception. I have >> told the users this is a 98% link and it WILL go down during those events. >> Earlier this winter we had a few days of ducting which caused a couple of >> them to fade. I saw a 15 dB fade on those. Statistically, ducting should >> only affect this area 20 some hours a year. >> >> >> >> The single exception was when the obstructing hill had
