Re: [WISPA] 900 Downtilt at 300'
Interesting, I never would have thought that much. I was thinking more of about 3-4 degrees. -Original Message- From: wireless-boun...@wispa.org [mailto:wireless-boun...@wispa.org] On Behalf Of Tom DeReggi Sent: Monday, March 09, 2009 11:43 PM To: WISPA General List Subject: Re: [WISPA] 900 Downtilt at 300' I disagree, Precise Tilt does matter quite a bit with Tiltek 900Mhz sectors. Let me give an example of mounted at 400ft with Tiltek sectors having 17 deg vert beamwidth. 8 deg downtilt, min .25 miles, max horizon. 9 degree downtilt, min .24 miles, max 8.6 miles. 10 degree downtilt, Min distance .22 miles, Max distance 2.8 miles. 11 deg downtilt, min .21 miles, Max 1.7 miles Near field coverage is rarely a problem with 900Mhz, regardless of the tilt. But what people forget is how much the far field is effected by just a single degree. The difference between 9 versus10 degrees is the difference of 5 miles ! coverage at optimal signal strength. The difference between 8 versus 10 degrees is the difference of whether you interfere with your other towers 30 miles away versus 3 miles away. With 900Mhz, EVERY DB counts. The reason is two fold. 1) The noise floor is ften high. 2) Its very easy to get colocated AP antenna self interference, when foliage can degrade the signal of a single link severally. For example, the Front-to-back isolation loss could be equivellent to the loss of foliage in a path. The goal is to get the highest signal uniformally to the largest area within your desired coverage area. Then you can always lower CPE transmit power as needed on links without foliage loss. In my 900 deployments, I have found that 3db lost or gained can be the difference between a typically good versus bad link. Now, its true the above beamwidths are only the distances that show 3 db loss, so a 10 degree downtilt, sector will still have a significant amount of signal going out to and heard from the the horizon. But every DB counts. The critical question becomes do you mount high or not? Higher avoids more trees. HIgher hears more interference. We found what was best for us was to go higher, but add more downtilt. We shoot for 10 degree downtilt. But it can be a delicate balance, dependent on your environment and noise levels and locations. We will usally put a larger focus on reducing noise to our adjacent cell sites, even if at the cost of gain to our intended coverage area. Tom DeReggi RapidDSL Wireless, Inc IntAirNet- Fixed Wireless Broadband - Original Message - From: Cliff Olle w...@eccentrixtechnologies.com To: 'WISPA General List' wireless@wispa.org Sent: Monday, March 09, 2009 9:25 PM Subject: [WISPA] 900 Downtilt at 300' For the 900 Mhz connectorized AP (by cyclone) with the 120 tiltek antenna, if I am mounted at 300', what amount of down tilt is normal? 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/ -- No virus found in this incoming message. Checked by AVG. Version: 7.5.557 / Virus Database: 270.11.9/1991 - Release Date: 3/9/2009 7:14 AM 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/
Re: [WISPA] 900 Downtilt at 300'
What is the terrain like? How much foliage are you trying to get through? __ Jerry Richardson airCloud Communications -Original Message- From: wireless-boun...@wispa.org [mailto:wireless-boun...@wispa.org] On Behalf Of Cliff Olle Sent: Monday, March 09, 2009 10:42 PM To: lakel...@gbcx.net; 'WISPA General List' Subject: Re: [WISPA] 900 Downtilt at 300' 10-12 miles -Original Message- From: wireless-boun...@wispa.org [mailto:wireless-boun...@wispa.org] On Behalf Of lakel...@gbcx.net Sent: Monday, March 09, 2009 8:36 PM To: WISPA General List Subject: Re: [WISPA] 900 Downtilt at 300' Depends on your distance to the target audience Sent from my Verizon Wireless BlackBerry -Original Message- From: Cliff Olle w...@eccentrixtechnologies.com Date: Mon, 9 Mar 2009 20:25:10 To: 'WISPA General List'wireless@wispa.org Subject: [WISPA] 900 Downtilt at 300' For the 900 Mhz connectorized AP (by cyclone) with the 120 tiltek antenna, if I am mounted at 300', what amount of down tilt is normal? 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/ 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/
Re: [WISPA] 900 Downtilt at 300'
I'm following this thread trying to pick up a general rule of thumb to start out with for down tilt (I have 2.4 systems though). I've seen three different methods of calculating it specified. 1). Downtilt enough so all your customers fall within the main lobe's -3 db line. 2). Downtilt so that your beam is focused half-way to your recommended coverage. 3). Downtilt so that you reach the furthest customer in your projected coverage area. These all seem mutually exclusive, unless I'm missing something. Regards Michael Baird I disagree, Precise Tilt does matter quite a bit with Tiltek 900Mhz sectors. Let me give an example of mounted at 400ft with Tiltek sectors having 17 deg vert beamwidth. 8 deg downtilt, min .25 miles, max horizon. 9 degree downtilt, min .24 miles, max 8.6 miles. 10 degree downtilt, Min distance .22 miles, Max distance 2.8 miles. 11 deg downtilt, min .21 miles, Max 1.7 miles Near field coverage is rarely a problem with 900Mhz, regardless of the tilt. But what people forget is how much the far field is effected by just a single degree. The difference between 9 versus10 degrees is the difference of 5 miles ! coverage at optimal signal strength. The difference between 8 versus 10 degrees is the difference of whether you interfere with your other towers 30 miles away versus 3 miles away. With 900Mhz, EVERY DB counts. The reason is two fold. 1) The noise floor is ften high. 2) Its very easy to get colocated AP antenna self interference, when foliage can degrade the signal of a single link severally. For example, the Front-to-back isolation loss could be equivellent to the loss of foliage in a path. The goal is to get the highest signal uniformally to the largest area within your desired coverage area. Then you can always lower CPE transmit power as needed on links without foliage loss. In my 900 deployments, I have found that 3db lost or gained can be the difference between a typically good versus bad link. Now, its true the above beamwidths are only the distances that show 3 db loss, so a 10 degree downtilt, sector will still have a significant amount of signal going out to and heard from the the horizon. But every DB counts. The critical question becomes do you mount high or not? Higher avoids more trees. HIgher hears more interference. We found what was best for us was to go higher, but add more downtilt. We shoot for 10 degree downtilt. But it can be a delicate balance, dependent on your environment and noise levels and locations. We will usally put a larger focus on reducing noise to our adjacent cell sites, even if at the cost of gain to our intended coverage area. Tom DeReggi RapidDSL Wireless, Inc IntAirNet- Fixed Wireless Broadband - Original Message - From: Cliff Olle w...@eccentrixtechnologies.com To: 'WISPA General List' wireless@wispa.org Sent: Monday, March 09, 2009 9:25 PM Subject: [WISPA] 900 Downtilt at 300' For the 900 Mhz connectorized AP (by cyclone) with the 120 tiltek antenna, if I am mounted at 300', what amount of down tilt is normal? 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/ -- No virus found in this incoming message. Checked by AVG. Version: 7.5.557 / Virus Database: 270.11.9/1991 - Release Date: 3/9/2009 7:14 AM 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/
Re: [WISPA] 900 Downtilt at 300'
The best way to do this is to set up a cpe unit at your FURTHEST customer site and one at your CLOSEST site. Aim for the best signal at the furthest site, then check at the closest site. If you need more signal at the closer site just aim down a little bit more and make sure that the signal is still OK at the far site. Me, I just eyeball them. Antennas are far from perfect. A couple of * off will normally make little or no difference in real world coverage. marlon - Original Message - From: Cliff Olle w...@eccentrixtechnologies.com To: 'WISPA General List' wireless@wispa.org Sent: Monday, March 09, 2009 10:51 PM Subject: Re: [WISPA] 900 Downtilt at 300' Interesting, I never would have thought that much. I was thinking more of about 3-4 degrees. -Original Message- From: wireless-boun...@wispa.org [mailto:wireless-boun...@wispa.org] On Behalf Of Tom DeReggi Sent: Monday, March 09, 2009 11:43 PM To: WISPA General List Subject: Re: [WISPA] 900 Downtilt at 300' I disagree, Precise Tilt does matter quite a bit with Tiltek 900Mhz sectors. Let me give an example of mounted at 400ft with Tiltek sectors having 17 deg vert beamwidth. 8 deg downtilt, min .25 miles, max horizon. 9 degree downtilt, min .24 miles, max 8.6 miles. 10 degree downtilt, Min distance .22 miles, Max distance 2.8 miles. 11 deg downtilt, min .21 miles, Max 1.7 miles Near field coverage is rarely a problem with 900Mhz, regardless of the tilt. But what people forget is how much the far field is effected by just a single degree. The difference between 9 versus10 degrees is the difference of 5 miles ! coverage at optimal signal strength. The difference between 8 versus 10 degrees is the difference of whether you interfere with your other towers 30 miles away versus 3 miles away. With 900Mhz, EVERY DB counts. The reason is two fold. 1) The noise floor is ften high. 2) Its very easy to get colocated AP antenna self interference, when foliage can degrade the signal of a single link severally. For example, the Front-to-back isolation loss could be equivellent to the loss of foliage in a path. The goal is to get the highest signal uniformally to the largest area within your desired coverage area. Then you can always lower CPE transmit power as needed on links without foliage loss. In my 900 deployments, I have found that 3db lost or gained can be the difference between a typically good versus bad link. Now, its true the above beamwidths are only the distances that show 3 db loss, so a 10 degree downtilt, sector will still have a significant amount of signal going out to and heard from the the horizon. But every DB counts. The critical question becomes do you mount high or not? Higher avoids more trees. HIgher hears more interference. We found what was best for us was to go higher, but add more downtilt. We shoot for 10 degree downtilt. But it can be a delicate balance, dependent on your environment and noise levels and locations. We will usally put a larger focus on reducing noise to our adjacent cell sites, even if at the cost of gain to our intended coverage area. Tom DeReggi RapidDSL Wireless, Inc IntAirNet- Fixed Wireless Broadband - Original Message - From: Cliff Olle w...@eccentrixtechnologies.com To: 'WISPA General List' wireless@wispa.org Sent: Monday, March 09, 2009 9:25 PM Subject: [WISPA] 900 Downtilt at 300' For the 900 Mhz connectorized AP (by cyclone) with the 120 tiltek antenna, if I am mounted at 300', what amount of down tilt is normal? 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/ -- No virus found in this incoming message. Checked by AVG. Version: 7.5.557 / Virus Database: 270.11.9/1991 - Release Date: 3/9/2009 7:14 AM 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
Re: [WISPA] 900 Downtilt at 300'
The nicer the antenna, the more critical the aim is. A cheap 900 sector will create a forgiving coverage pattern. A nice one like Tiltek or MTI will have a well defined coverage pattern in the vertical direction. Personally, I wouldn't put 900 that high on a tower, as it would receive too much interference in my areas. I'd be hesitant to put 900 over 150 feet. But anything going that high up should be a high quality antenna, anything else is false economy in the event it needs repair or replacement. On Tue, Mar 10, 2009 at 12:42:57AM -0400, Tom DeReggi wrote: I disagree, Precise Tilt does matter quite a bit with Tiltek 900Mhz sectors. Let me give an example of mounted at 400ft with Tiltek sectors having 17 deg vert beamwidth. 8 deg downtilt, min .25 miles, max horizon. 9 degree downtilt, min .24 miles, max 8.6 miles. 10 degree downtilt, Min distance .22 miles, Max distance 2.8 miles. 11 deg downtilt, min .21 miles, Max 1.7 miles Near field coverage is rarely a problem with 900Mhz, regardless of the tilt. But what people forget is how much the far field is effected by just a single degree. The difference between 9 versus10 degrees is the difference of 5 miles ! coverage at optimal signal strength. The difference between 8 versus 10 degrees is the difference of whether you interfere with your other towers 30 miles away versus 3 miles away. With 900Mhz, EVERY DB counts. The reason is two fold. 1) The noise floor is ften high. 2) Its very easy to get colocated AP antenna self interference, when foliage can degrade the signal of a single link severally. For example, the Front-to-back isolation loss could be equivellent to the loss of foliage in a path. The goal is to get the highest signal uniformally to the largest area within your desired coverage area. Then you can always lower CPE transmit power as needed on links without foliage loss. In my 900 deployments, I have found that 3db lost or gained can be the difference between a typically good versus bad link. Now, its true the above beamwidths are only the distances that show 3 db loss, so a 10 degree downtilt, sector will still have a significant amount of signal going out to and heard from the the horizon. But every DB counts. The critical question becomes do you mount high or not? Higher avoids more trees. HIgher hears more interference. We found what was best for us was to go higher, but add more downtilt. We shoot for 10 degree downtilt. But it can be a delicate balance, dependent on your environment and noise levels and locations. We will usally put a larger focus on reducing noise to our adjacent cell sites, even if at the cost of gain to our intended coverage area. Tom DeReggi RapidDSL Wireless, Inc IntAirNet- Fixed Wireless Broadband - Original Message - From: Cliff Olle w...@eccentrixtechnologies.com To: 'WISPA General List' wireless@wispa.org Sent: Monday, March 09, 2009 9:25 PM Subject: [WISPA] 900 Downtilt at 300' For the 900 Mhz connectorized AP (by cyclone) with the 120 tiltek antenna, if I am mounted at 300', what amount of down tilt is normal? 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/ -- No virus found in this incoming message. Checked by AVG. Version: 7.5.557 / Virus Database: 270.11.9/1991 - Release Date: 3/9/2009 7:14 AM 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/ -- /* Jason Philbrook | Midcoast Internet Solutions - Wireless and DSL KB1IOJ| Broadband Internet Access, Dialup, and Hosting http://f64.nu/ | for Midcoast Mainehttp://www.midcoast.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/
Re: [WISPA] 900 Downtilt at 300'
They all work because antennas do NOT just stop radiating in a given direction. They actually send energy all over the place, it's just stronger in one direction than in the others. We often talk about antennas like a flashlight, but that's not really quite accurate. It's more like a light bulb with a sheet of paper behind it. You'll not see as much light, depending on the type of paper, but you'll still see some. Same thing goes for the sides marlon - Original Message - From: Michael Baird m...@tc3net.com To: WISPA General List wireless@wispa.org Sent: Tuesday, March 10, 2009 5:53 AM Subject: Re: [WISPA] 900 Downtilt at 300' I'm following this thread trying to pick up a general rule of thumb to start out with for down tilt (I have 2.4 systems though). I've seen three different methods of calculating it specified. 1). Downtilt enough so all your customers fall within the main lobe's -3 db line. 2). Downtilt so that your beam is focused half-way to your recommended coverage. 3). Downtilt so that you reach the furthest customer in your projected coverage area. These all seem mutually exclusive, unless I'm missing something. Regards Michael Baird I disagree, Precise Tilt does matter quite a bit with Tiltek 900Mhz sectors. Let me give an example of mounted at 400ft with Tiltek sectors having 17 deg vert beamwidth. 8 deg downtilt, min .25 miles, max horizon. 9 degree downtilt, min .24 miles, max 8.6 miles. 10 degree downtilt, Min distance .22 miles, Max distance 2.8 miles. 11 deg downtilt, min .21 miles, Max 1.7 miles Near field coverage is rarely a problem with 900Mhz, regardless of the tilt. But what people forget is how much the far field is effected by just a single degree. The difference between 9 versus10 degrees is the difference of 5 miles ! coverage at optimal signal strength. The difference between 8 versus 10 degrees is the difference of whether you interfere with your other towers 30 miles away versus 3 miles away. With 900Mhz, EVERY DB counts. The reason is two fold. 1) The noise floor is ften high. 2) Its very easy to get colocated AP antenna self interference, when foliage can degrade the signal of a single link severally. For example, the Front-to-back isolation loss could be equivellent to the loss of foliage in a path. The goal is to get the highest signal uniformally to the largest area within your desired coverage area. Then you can always lower CPE transmit power as needed on links without foliage loss. In my 900 deployments, I have found that 3db lost or gained can be the difference between a typically good versus bad link. Now, its true the above beamwidths are only the distances that show 3 db loss, so a 10 degree downtilt, sector will still have a significant amount of signal going out to and heard from the the horizon. But every DB counts. The critical question becomes do you mount high or not? Higher avoids more trees. HIgher hears more interference. We found what was best for us was to go higher, but add more downtilt. We shoot for 10 degree downtilt. But it can be a delicate balance, dependent on your environment and noise levels and locations. We will usally put a larger focus on reducing noise to our adjacent cell sites, even if at the cost of gain to our intended coverage area. Tom DeReggi RapidDSL Wireless, Inc IntAirNet- Fixed Wireless Broadband - Original Message - From: Cliff Olle w...@eccentrixtechnologies.com To: 'WISPA General List' wireless@wispa.org Sent: Monday, March 09, 2009 9:25 PM Subject: [WISPA] 900 Downtilt at 300' For the 900 Mhz connectorized AP (by cyclone) with the 120 tiltek antenna, if I am mounted at 300', what amount of down tilt is normal? 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/ -- No virus found in this incoming message. Checked by AVG. Version: 7.5.557 / Virus Database: 270.11.9/1991 - Release Date: 3/9/2009 7:14 AM 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
Re: [WISPA] 900 Downtilt at 300'
I'd argue none of the 3 above. For 900Mhz and 2.4Ghz (because of wider Verticle beamwidths) I'd advise Downtilt until your mainlobe (3db mark) edge is no longer going beyond your maximum intended coverage range, or a bit more, if you can afford further isolation from the potential adjacent cell interference source. The primary goal is to keep harmfull interference from shooting off to the horizon (ultimately protecting your network since receive gain/beamwidth is reciprocal). How much tilt is required to do that, depends on the antenna beamwidth, and the height that you decide to install at, for what ever reason. In 5.8G its less critical because you can make up for it on CPE side antenna side, and ther eare much fewer noise sources at 5.8Ghz. That is until your 5.8G area gets congested :-( But because 5.8G may have smaller verticle beamwidths, the nearfield potentially could be more of a concern, that the other freqs. Tom DeReggi RapidDSL Wireless, Inc IntAirNet- Fixed Wireless Broadband - Original Message - From: Michael Baird m...@tc3net.com To: WISPA General List wireless@wispa.org Sent: Tuesday, March 10, 2009 8:53 AM Subject: Re: [WISPA] 900 Downtilt at 300' I'm following this thread trying to pick up a general rule of thumb to start out with for down tilt (I have 2.4 systems though). I've seen three different methods of calculating it specified. 1). Downtilt enough so all your customers fall within the main lobe's -3 db line. 2). Downtilt so that your beam is focused half-way to your recommended coverage. 3). Downtilt so that you reach the furthest customer in your projected coverage area. These all seem mutually exclusive, unless I'm missing something. Regards Michael Baird I disagree, Precise Tilt does matter quite a bit with Tiltek 900Mhz sectors. Let me give an example of mounted at 400ft with Tiltek sectors having 17 deg vert beamwidth. 8 deg downtilt, min .25 miles, max horizon. 9 degree downtilt, min .24 miles, max 8.6 miles. 10 degree downtilt, Min distance .22 miles, Max distance 2.8 miles. 11 deg downtilt, min .21 miles, Max 1.7 miles Near field coverage is rarely a problem with 900Mhz, regardless of the tilt. But what people forget is how much the far field is effected by just a single degree. The difference between 9 versus10 degrees is the difference of 5 miles ! coverage at optimal signal strength. The difference between 8 versus 10 degrees is the difference of whether you interfere with your other towers 30 miles away versus 3 miles away. With 900Mhz, EVERY DB counts. The reason is two fold. 1) The noise floor is ften high. 2) Its very easy to get colocated AP antenna self interference, when foliage can degrade the signal of a single link severally. For example, the Front-to-back isolation loss could be equivellent to the loss of foliage in a path. The goal is to get the highest signal uniformally to the largest area within your desired coverage area. Then you can always lower CPE transmit power as needed on links without foliage loss. In my 900 deployments, I have found that 3db lost or gained can be the difference between a typically good versus bad link. Now, its true the above beamwidths are only the distances that show 3 db loss, so a 10 degree downtilt, sector will still have a significant amount of signal going out to and heard from the the horizon. But every DB counts. The critical question becomes do you mount high or not? Higher avoids more trees. HIgher hears more interference. We found what was best for us was to go higher, but add more downtilt. We shoot for 10 degree downtilt. But it can be a delicate balance, dependent on your environment and noise levels and locations. We will usally put a larger focus on reducing noise to our adjacent cell sites, even if at the cost of gain to our intended coverage area. Tom DeReggi RapidDSL Wireless, Inc IntAirNet- Fixed Wireless Broadband - Original Message - From: Cliff Olle w...@eccentrixtechnologies.com To: 'WISPA General List' wireless@wispa.org Sent: Monday, March 09, 2009 9:25 PM Subject: [WISPA] 900 Downtilt at 300' For the 900 Mhz connectorized AP (by cyclone) with the 120 tiltek antenna, if I am mounted at 300', what amount of down tilt is normal? 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/ -- No virus found in this incoming message. Checked by AVG. Version: 7.5.557 / Virus Database: 270.11.9/1991 - Release Date: 3/9/2009 7:14 AM
Re: [WISPA] 900 Downtilt at 300'
Thats what I thought to, originally. Originally it was a Horiz omni at 175ft, vert omni at 150 feet. Then it became 3 sectors at 200ft. (I have 70-100ft mature trees around) But I had to move them up. I was able to double my customer coverage area by going to 425ft high. There becomes a ratio of how much loss your trees give compared to the interference of going higher. In my case thick pine trees, and dirt on rolling hills, caused much more loss than interference did. (And I was in very high Interference areas) Height was absolutely required, because it minimized the number of tree tops that the signal had to go through significantly. (Actually its feasible my antennas were at heights above the noise height, at 425 ft, considering many interfering rooftop 900Mhz antennas were on 5 story height buildings in nearby cities) But when being that high Adequate downtilt was absolutely required. I wanted to restrict to 3-5 mile coverage, for my core target. As was Horizontal pol, and High quality F/B ratio Tiltek sectors, as was 10-15 feet min verticle seperation per antenna. Tom DeReggi RapidDSL Wireless, Inc IntAirNet- Fixed Wireless Broadband - Original Message - From: jp j...@saucer.midcoast.com To: WISPA General List wireless@wispa.org Sent: Tuesday, March 10, 2009 9:39 AM Subject: Re: [WISPA] 900 Downtilt at 300' The nicer the antenna, the more critical the aim is. A cheap 900 sector will create a forgiving coverage pattern. A nice one like Tiltek or MTI will have a well defined coverage pattern in the vertical direction. Personally, I wouldn't put 900 that high on a tower, as it would receive too much interference in my areas. I'd be hesitant to put 900 over 150 feet. But anything going that high up should be a high quality antenna, anything else is false economy in the event it needs repair or replacement. On Tue, Mar 10, 2009 at 12:42:57AM -0400, Tom DeReggi wrote: I disagree, Precise Tilt does matter quite a bit with Tiltek 900Mhz sectors. Let me give an example of mounted at 400ft with Tiltek sectors having 17 deg vert beamwidth. 8 deg downtilt, min .25 miles, max horizon. 9 degree downtilt, min .24 miles, max 8.6 miles. 10 degree downtilt, Min distance .22 miles, Max distance 2.8 miles. 11 deg downtilt, min .21 miles, Max 1.7 miles Near field coverage is rarely a problem with 900Mhz, regardless of the tilt. But what people forget is how much the far field is effected by just a single degree. The difference between 9 versus10 degrees is the difference of 5 miles ! coverage at optimal signal strength. The difference between 8 versus 10 degrees is the difference of whether you interfere with your other towers 30 miles away versus 3 miles away. With 900Mhz, EVERY DB counts. The reason is two fold. 1) The noise floor is ften high. 2) Its very easy to get colocated AP antenna self interference, when foliage can degrade the signal of a single link severally. For example, the Front-to-back isolation loss could be equivellent to the loss of foliage in a path. The goal is to get the highest signal uniformally to the largest area within your desired coverage area. Then you can always lower CPE transmit power as needed on links without foliage loss. In my 900 deployments, I have found that 3db lost or gained can be the difference between a typically good versus bad link. Now, its true the above beamwidths are only the distances that show 3 db loss, so a 10 degree downtilt, sector will still have a significant amount of signal going out to and heard from the the horizon. But every DB counts. The critical question becomes do you mount high or not? Higher avoids more trees. HIgher hears more interference. We found what was best for us was to go higher, but add more downtilt. We shoot for 10 degree downtilt. But it can be a delicate balance, dependent on your environment and noise levels and locations. We will usally put a larger focus on reducing noise to our adjacent cell sites, even if at the cost of gain to our intended coverage area. Tom DeReggi RapidDSL Wireless, Inc IntAirNet- Fixed Wireless Broadband - Original Message - From: Cliff Olle w...@eccentrixtechnologies.com To: 'WISPA General List' wireless@wispa.org Sent: Monday, March 09, 2009 9:25 PM Subject: [WISPA] 900 Downtilt at 300' For the 900 Mhz connectorized AP (by cyclone) with the 120 tiltek antenna, if I am mounted at 300', what amount of down tilt is normal? 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/ -- No virus found
Re: [WISPA] 900 Downtilt at 300'
Tom, that's option 1, which I think you suggested earlier, and why I put it on my list. 1). Downtilt enough so all customers fall within the main lobes -3db mark. Regards Michael Baird I'd argue none of the 3 above. For 900Mhz and 2.4Ghz (because of wider Verticle beamwidths) I'd advise Downtilt until your mainlobe (3db mark) edge is no longer going beyond your maximum intended coverage range, or a bit more, if you can afford further isolation from the potential adjacent cell interference source. The primary goal is to keep harmfull interference from shooting off to the horizon (ultimately protecting your network since receive gain/beamwidth is reciprocal). How much tilt is required to do that, depends on the antenna beamwidth, and the height that you decide to install at, for what ever reason. In 5.8G its less critical because you can make up for it on CPE side antenna side, and ther eare much fewer noise sources at 5.8Ghz. That is until your 5.8G area gets congested :-( But because 5.8G may have smaller verticle beamwidths, the nearfield potentially could be more of a concern, that the other freqs. Tom DeReggi RapidDSL Wireless, Inc IntAirNet- Fixed Wireless Broadband - Original Message - From: Michael Baird m...@tc3net.com To: WISPA General List wireless@wispa.org Sent: Tuesday, March 10, 2009 8:53 AM Subject: Re: [WISPA] 900 Downtilt at 300' I'm following this thread trying to pick up a general rule of thumb to start out with for down tilt (I have 2.4 systems though). I've seen three different methods of calculating it specified. 1). Downtilt enough so all your customers fall within the main lobe's -3 db line. 2). Downtilt so that your beam is focused half-way to your recommended coverage. 3). Downtilt so that you reach the furthest customer in your projected coverage area. These all seem mutually exclusive, unless I'm missing something. Regards Michael Baird I disagree, Precise Tilt does matter quite a bit with Tiltek 900Mhz sectors. Let me give an example of mounted at 400ft with Tiltek sectors having 17 deg vert beamwidth. 8 deg downtilt, min .25 miles, max horizon. 9 degree downtilt, min .24 miles, max 8.6 miles. 10 degree downtilt, Min distance .22 miles, Max distance 2.8 miles. 11 deg downtilt, min .21 miles, Max 1.7 miles Near field coverage is rarely a problem with 900Mhz, regardless of the tilt. But what people forget is how much the far field is effected by just a single degree. The difference between 9 versus10 degrees is the difference of 5 miles ! coverage at optimal signal strength. The difference between 8 versus 10 degrees is the difference of whether you interfere with your other towers 30 miles away versus 3 miles away. With 900Mhz, EVERY DB counts. The reason is two fold. 1) The noise floor is ften high. 2) Its very easy to get colocated AP antenna self interference, when foliage can degrade the signal of a single link severally. For example, the Front-to-back isolation loss could be equivellent to the loss of foliage in a path. The goal is to get the highest signal uniformally to the largest area within your desired coverage area. Then you can always lower CPE transmit power as needed on links without foliage loss. In my 900 deployments, I have found that 3db lost or gained can be the difference between a typically good versus bad link. Now, its true the above beamwidths are only the distances that show 3 db loss, so a 10 degree downtilt, sector will still have a significant amount of signal going out to and heard from the the horizon. But every DB counts. The critical question becomes do you mount high or not? Higher avoids more trees. HIgher hears more interference. We found what was best for us was to go higher, but add more downtilt. We shoot for 10 degree downtilt. But it can be a delicate balance, dependent on your environment and noise levels and locations. We will usally put a larger focus on reducing noise to our adjacent cell sites, even if at the cost of gain to our intended coverage area. Tom DeReggi RapidDSL Wireless, Inc IntAirNet- Fixed Wireless Broadband - Original Message - From: Cliff Olle w...@eccentrixtechnologies.com To: 'WISPA General List' wireless@wispa.org Sent: Monday, March 09, 2009 9:25 PM Subject: [WISPA] 900 Downtilt at 300' For the 900 Mhz connectorized AP (by cyclone) with the 120 tiltek antenna, if I am mounted at 300', what amount of down tilt is normal? 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] 900 Downtilt at 300'
For the 900 Mhz connectorized AP (by cyclone) with the 120 tiltek antenna, if I am mounted at 300', what amount of down tilt is normal? 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/
Re: [WISPA] 900 Downtilt at 300'
Depends on your distance to the target audience Sent from my Verizon Wireless BlackBerry -Original Message- From: Cliff Olle w...@eccentrixtechnologies.com Date: Mon, 9 Mar 2009 20:25:10 To: 'WISPA General List'wireless@wispa.org Subject: [WISPA] 900 Downtilt at 300' For the 900 Mhz connectorized AP (by cyclone) with the 120 tiltek antenna, if I am mounted at 300', what amount of down tilt is normal? 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/
Re: [WISPA] 900 Downtilt at 300'
http://www.wisp-router.com/calculators/downtilt.php You want your customers inside your inner and outer 3dB radius. /Eje --Original Message-- From: Cliff Olle Sender: wireless-boun...@wispa.org To: 'WISPA General List' ReplyTo: WISPA General List Subject: [WISPA] 900 Downtilt at 300' Sent: Mar 9, 2009 20:25 For the 900 Mhz connectorized AP (by cyclone) with the 120 tiltek antenna, if I am mounted at 300', what amount of down tilt is normal? 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/ Sent via BlackBerry from T-Mobile 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/
Re: [WISPA] 900 Downtilt at 300'
Sure, but what if the 3db radius is at the horizon, on the wisp-router.com site, it has a sweet spot, what does that mean exactly, where the main lobe falls? Should you try to downtilt enough so the outer radius is not at the horizon? Regards Michael Baird http://www.wisp-router.com/calculators/downtilt.php You want your customers inside your inner and outer 3dB radius. /Eje --Original Message-- From: Cliff Olle Sender: wireless-boun...@wispa.org To: 'WISPA General List' ReplyTo: WISPA General List Subject: [WISPA] 900 Downtilt at 300' Sent: Mar 9, 2009 20:25 For the 900 Mhz connectorized AP (by cyclone) with the 120 tiltek antenna, if I am mounted at 300', what amount of down tilt is normal? 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/ Sent via BlackBerry from T-Mobile 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/
Re: [WISPA] 900 Downtilt at 300'
In practice I don't think it matters a lot with 900Mhz... JMHO Scott Carullo Brevard Wireless 321-205-1100 x102 Original Message From: Cliff Olle w...@eccentrixtechnologies.com Sent: Monday, March 09, 2009 9:31 PM To: WISPA General List wireless@wispa.org Subject: [WISPA] 900 Downtilt at 300' For the 900 Mhz connectorized AP (by cyclone) with the 120 tiltek antenna, if I am mounted at 300', what amount of down tilt is normal? 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/
Re: [WISPA] 900 Downtilt at 300'
Generally not on a 900Mhz with wide beam. But height get more important when dealing with say a 11dB omni. On the Tiltek (believe it's a 19deg H-plane beam) I would probably consider 1-2 degree downtilt would get the sweet spot at at either 1.6miles or 3.3 miles out and the inner -3dB at a quarter to a third mile out. In 900Mhz generally in most cases I have not seen much of problems within a mile from the tower. 1+ miles out can sometimes be a hassle. So question is where one want the strongest signal. To close in and you might not have enough signal where it counts. To far out you might get spotty coverage in the mid field. But 900 is 900 so it's not that picky as Scott states. / Eje -Original Message- From: wireless-boun...@wispa.org [mailto:wireless-boun...@wispa.org] On Behalf Of Scott Carullo Sent: Monday, March 09, 2009 9:41 PM To: WISPA General List Subject: Re: [WISPA] 900 Downtilt at 300' In practice I don't think it matters a lot with 900Mhz... JMHO Scott Carullo Brevard Wireless 321-205-1100 x102 Original Message From: Cliff Olle w...@eccentrixtechnologies.com Sent: Monday, March 09, 2009 9:31 PM To: WISPA General List wireless@wispa.org Subject: [WISPA] 900 Downtilt at 300' For the 900 Mhz connectorized AP (by cyclone) with the 120 tiltek antenna, if I am mounted at 300', what amount of down tilt is normal? 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/
Re: [WISPA] 900 Downtilt at 300'
I disagree, Precise Tilt does matter quite a bit with Tiltek 900Mhz sectors. Let me give an example of mounted at 400ft with Tiltek sectors having 17 deg vert beamwidth. 8 deg downtilt, min .25 miles, max horizon. 9 degree downtilt, min .24 miles, max 8.6 miles. 10 degree downtilt, Min distance .22 miles, Max distance 2.8 miles. 11 deg downtilt, min .21 miles, Max 1.7 miles Near field coverage is rarely a problem with 900Mhz, regardless of the tilt. But what people forget is how much the far field is effected by just a single degree. The difference between 9 versus10 degrees is the difference of 5 miles ! coverage at optimal signal strength. The difference between 8 versus 10 degrees is the difference of whether you interfere with your other towers 30 miles away versus 3 miles away. With 900Mhz, EVERY DB counts. The reason is two fold. 1) The noise floor is ften high. 2) Its very easy to get colocated AP antenna self interference, when foliage can degrade the signal of a single link severally. For example, the Front-to-back isolation loss could be equivellent to the loss of foliage in a path. The goal is to get the highest signal uniformally to the largest area within your desired coverage area. Then you can always lower CPE transmit power as needed on links without foliage loss. In my 900 deployments, I have found that 3db lost or gained can be the difference between a typically good versus bad link. Now, its true the above beamwidths are only the distances that show 3 db loss, so a 10 degree downtilt, sector will still have a significant amount of signal going out to and heard from the the horizon. But every DB counts. The critical question becomes do you mount high or not? Higher avoids more trees. HIgher hears more interference. We found what was best for us was to go higher, but add more downtilt. We shoot for 10 degree downtilt. But it can be a delicate balance, dependent on your environment and noise levels and locations. We will usally put a larger focus on reducing noise to our adjacent cell sites, even if at the cost of gain to our intended coverage area. Tom DeReggi RapidDSL Wireless, Inc IntAirNet- Fixed Wireless Broadband - Original Message - From: Cliff Olle w...@eccentrixtechnologies.com To: 'WISPA General List' wireless@wispa.org Sent: Monday, March 09, 2009 9:25 PM Subject: [WISPA] 900 Downtilt at 300' For the 900 Mhz connectorized AP (by cyclone) with the 120 tiltek antenna, if I am mounted at 300', what amount of down tilt is normal? 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/ -- No virus found in this incoming message. Checked by AVG. Version: 7.5.557 / Virus Database: 270.11.9/1991 - Release Date: 3/9/2009 7:14 AM 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/
Re: [WISPA] 900 Downtilt at 300'
10-12 miles -Original Message- From: wireless-boun...@wispa.org [mailto:wireless-boun...@wispa.org] On Behalf Of lakel...@gbcx.net Sent: Monday, March 09, 2009 8:36 PM To: WISPA General List Subject: Re: [WISPA] 900 Downtilt at 300' Depends on your distance to the target audience Sent from my Verizon Wireless BlackBerry -Original Message- From: Cliff Olle w...@eccentrixtechnologies.com Date: Mon, 9 Mar 2009 20:25:10 To: 'WISPA General List'wireless@wispa.org Subject: [WISPA] 900 Downtilt at 300' For the 900 Mhz connectorized AP (by cyclone) with the 120 tiltek antenna, if I am mounted at 300', what amount of down tilt is normal? 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/
