Re: [WISPA] 180* sector choices
Not really. True, using 10 MHz-wide channels instead of 22 MHz-wide channels should help protect the adjacent-channel receivers from overloading and the resulting throughput reduction. The downside is that a narrower 10 MHz-wide channel won't deliver as much throughput as a wider 22 MHz channel - everything else (over-the-air protocol, interference levels, etc.) being equal. Because the aggregate throughput of the 10 MHz-wide channel site will be lower than a 22 MHz-wide site, the site won't be able to serve as many customers. Rather than build a lower throughput system, I'd rather build a higher throughput system and just design in enough receiver overload protection by using the methods that we've already discussed. jack George Rogato wrote: Jack, If one was to use 3 10MHz channels with 10MHz seperation between channels, they would see the same or better performance than 3 full size channels side by side. So thats my advice, but it won't be wifi. Would be nice if there was a 5 gig option per sector so that you could do 2 2 gig channels at 1 and 11 and a 5 gig sector. George Jack Unger wrote: Rick, Here's what I see that's good about the Pac Wireless antenna: 1. The 3-in-1 design may be the only solution where only one antenna-mounting space exists on a tower. 2. The inclusion of electrical downtilt will minimize overshooting customers. 3. The inclusion of null fill will minimize connectivity problems with customers located very close to the tower. 4. The 15 dBi gain is in the appropriate and usable range. 5. The weight (14 lbs) will make the antenna easy to raise and mount. 6. The price range ($700) is moderate considering that you're really getting three sector antennas in one. Here's what I see that will need special consideration and planning. 1. The front-to-back ratio is only 15 dB. This is low compared to the 30 dB that I usually recommend for high-quality antennas. 2. The sector-to-sector isolation is 35 dB. When compared to the 83 dB of isolation that 10 feet of vertical separation would provide, 35 dB is a lot less. In summary, this appears to be a good antenna system with the one limitation that the somewhat low f/b ratio and sector-to-sector isolation will combine to place the burden for good AP-to-AP isolation on the quality of the co-located access point receivers and the quality of the overall AP/site design. Receivers with poor or moderate selectivity (in other words, receivers on Wi-Fi cards) will be overloaded by the other AP transmitters with the result being a throughput reduction that begins when traffic levels increase. The more traffic, the more missed incoming packets, the more retransmissions and the more throughput reduction. The result will be that the site reaches saturation sooner and won't handle as much traffic as a site where the AP receivers are not being overloaded. The solution (other than to use really expensive equipment which has good receiver filtering and selectivity built in) is to again use single-channel bandpass filters on each AP. These will reduce the level of signal from the co-located adjacent-channel AP transmitters and permit the site to handle more traffic (reach saturation later) than a site where the receivers ARE being overloaded. Finally, in addition to the above, it's important not to defeat the antenna isolation by letting RF energy leak directly from AP to AP either on the ground or from PC-card to PC card. Proper shielding and grounding will help to maintain that hard-won receiver-to-transmitter isolation resulting in a high-performance, high-traffic handling, reliable, profitable site. jack Rick Harnish wrote: Jack, While we are on this topic, look at the .pdf file and give me your comments on this all in one sector from Pac Wireless? Thanks, Rick Harnish President OnlyInternet Broadband Wireless, Inc. 260-827-2482 Founding Member of WISPA -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Jack Unger Sent: Friday, May 18, 2007 4:18 PM To: WISPA General List Subject: Re: [WISPA] 180* sector choices Mac, Thanks for replying to my concerns and suggestions. Have you tried using 5 to 10 feet of vertical separation between the antennas rather than mounting them all at the same height? 10 feet of vertical separation should be enough to prevent one AP transmitter from overloading another AP receiver. Secondly, single-channel bandpass filters are available which will provide additional receiver protection from nearby transmitters operating on non-overlapping frequencies. Finally, higher-priced antennas normally have a higher front-to-back ratio which increases isolation (minimizes interaction) between the antennas. A minimum f/b ratio of 30 dBm is recommended. Keep in mind that without dealing with these antenna isolation issues, you will likely have the same problems using two 180* sector antennas as you have
RE: [WISPA] 180* sector choices
That's what I am talking about Larry! Thanks Who all sales Til-Tek? Mac Dearman Maximum Access, LLC. Rayville, La. www.inetsouth.com www.radioresponse.org (Katrina relief) www.mac-tel.us (VoIP sales) 318.728.8600 318.728.9600 318.303.4182 -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Larry A Weidig Sent: Friday, May 18, 2007 8:39 AM To: WISPA General List Subject: RE: [WISPA] 180* sector choices Mac: We have used both of these with success: http://www.tiltek.com/final/pdfs/TA-2304-4-180-ISM.pdf http://www.tiltek.com/final/pdfs/TA-2304-2-180-ISM.pdf The second one is smaller and only has 12.5 dBi gain, the first one has 15 dBi. Just to be clear I have no association or affiliation with Til-Tek, just have used these on a couple of sites where three sectors (our typical setup as well) was not an option. Hope that helps. * Larry A. Weidig ([EMAIL PROTECTED]) * Excel.Net,Inc. - http://www.excel.net/ * (920) 452-0455 - Sheboygan/Plymouth area * (888) 489-9995 - Other areas, toll-free -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Mac Dearman Sent: Friday, May 18, 2007 8:26 AM To: 'WISPA General List' Subject: RE: [WISPA] 180* sector choices Does anyone on list have a set of 2.4GHz 180* sector antennas they would like to brag on? I have two towers that need to be sectored out and I am on the hunt. I would like to have as much gain as possible at the antenna. Any suggestions, comments and feed back are greatly appreciated as I have never deployed 180* sectors, but we have always used either Omni's or 3 120* sectors. These towers are just Rohn 25G and I cant seem to get enough separation up top for the 120* sectors. Been there done that and still fighting the issues it causes by mounting the 3 120* sectors too close to one another. Thanks folks, Mac -- 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/ -- WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/
RE: [WISPA] 180* sector choices
Does anyone on list have a set of 2.4GHz 180* sector antennas they would like to brag on? I have two towers that need to be sectored out and I am on the hunt. I would like to have as much gain as possible at the antenna. Any suggestions, comments and feed back are greatly appreciated as I have never deployed 180* sectors, but we have always used either Omni's or 3 120* sectors. These towers are just Rohn 25G and I cant seem to get enough separation up top for the 120* sectors. Been there done that and still fighting the issues it causes by mounting the 3 120* sectors too close to one another. Thanks folks, Mac -- WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/
RE: [WISPA] 180* sector choices
Mac: We have used both of these with success: http://www.tiltek.com/final/pdfs/TA-2304-4-180-ISM.pdf http://www.tiltek.com/final/pdfs/TA-2304-2-180-ISM.pdf The second one is smaller and only has 12.5 dBi gain, the first one has 15 dBi. Just to be clear I have no association or affiliation with Til-Tek, just have used these on a couple of sites where three sectors (our typical setup as well) was not an option. Hope that helps. * Larry A. Weidig ([EMAIL PROTECTED]) * Excel.Net,Inc. - http://www.excel.net/ * (920) 452-0455 - Sheboygan/Plymouth area * (888) 489-9995 - Other areas, toll-free -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Mac Dearman Sent: Friday, May 18, 2007 8:26 AM To: 'WISPA General List' Subject: RE: [WISPA] 180* sector choices Does anyone on list have a set of 2.4GHz 180* sector antennas they would like to brag on? I have two towers that need to be sectored out and I am on the hunt. I would like to have as much gain as possible at the antenna. Any suggestions, comments and feed back are greatly appreciated as I have never deployed 180* sectors, but we have always used either Omni's or 3 120* sectors. These towers are just Rohn 25G and I cant seem to get enough separation up top for the 120* sectors. Been there done that and still fighting the issues it causes by mounting the 3 120* sectors too close to one another. Thanks folks, Mac -- 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] 180* sector choices
I have been using the Comtelco 180s and they seem to work fine. Got them from Electrocom. Jory Privett WCCS - Original Message - From: Mac Dearman [EMAIL PROTECTED] To: 'WISPA General List' wireless@wispa.org Sent: Friday, May 18, 2007 8:26 AM Subject: RE: [WISPA] 180* sector choices Does anyone on list have a set of 2.4GHz 180* sector antennas they would like to brag on? I have two towers that need to be sectored out and I am on the hunt. I would like to have as much gain as possible at the antenna. Any suggestions, comments and feed back are greatly appreciated as I have never deployed 180* sectors, but we have always used either Omni's or 3 120* sectors. These towers are just Rohn 25G and I cant seem to get enough separation up top for the 120* sectors. Been there done that and still fighting the issues it causes by mounting the 3 120* sectors too close to one another. Thanks folks, Mac -- 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] 180* sector choices
Mac, Before you discard the idea of using three 120* sectors are you absolutely certain that the separation issue is really due to the antennas not being far enough apart? Have you thoroughly looked at other reasons why there could be interference between three APs like: 1. Using three cards on a single motherboard in one enclosure without sufficient shielding between them. 2. Using three APs that are configured on frequencies that are too close together and are interfering with each other? I guess what I'm asking is (before you go spend money on antennas that may or may not solve the problem) what equipment are you currently using, how is it configured, and how far apart can you actually get three sector antennas on the 25G tower? jack Mac Dearman wrote: Does anyone on list have a set of 2.4GHz 180* sector antennas they would like to brag on? I have two towers that need to be sectored out and I am on the hunt. I would like to have as much gain as possible at the antenna. Any suggestions, comments and feed back are greatly appreciated as I have never deployed 180* sectors, but we have always used either Omni's or 3 120* sectors. These towers are just Rohn 25G and I cant seem to get enough separation up top for the 120* sectors. Been there done that and still fighting the issues it causes by mounting the 3 120* sectors too close to one another. Thanks folks, Mac -- Jack Unger ([EMAIL PROTECTED]) - President, Ask-Wi.Com, Inc. FCC License # PG-12-25133 Serving the Broadband Wireless Industry Since 1993 Author of the WISP Handbook - Deploying License-Free Wireless WANs True Vendor-Neutral Wireless Consulting-Training-Troubleshooting FCC Part 15 Certification for Manufacturers and Service Providers Phone (VoIP Over Broadband Wireless) 818-227-4220 www.ask-wi.com -- WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/
RE: [WISPA] 180* sector choices
See in line please Behalf of Jack Unger Mac, Before you discard the idea of using three 120* sectors are you absolutely certain that the separation issue is really due to the antennas not being far enough apart? Have you thoroughly looked at other reasons why there could be interference between three APs like: [Mac says:] Well Jack - I'd like to think that I have exhausted the other possibilities :-) but I am always willing to listen. 1. Using three cards on a single motherboard in one enclosure without sufficient shielding between them. [Mac says:] All of our sector arrays utilize 3 different enclosures with one radio to the enclosure and then I try to separate the enclosures (and antennas) as far as possible. 2. Using three APs that are configured on frequencies that are too close together and are interfering with each other? [Mac says:] Unless we deploy 4 90* sectors we use non overlapping channels (1, 6 11) I guess what I'm asking is (before you go spend money on antennas that may or may not solve the problem) what equipment are you currently using, how is it configured, and how far apart can you actually get three sector antennas on the 25G tower? jack [Mac says:] I have come to the conclusion that it is interference from the backplane of the antennas due to not having adequate separation from each other. These small towers (although 180') like Rohn 25G aren't but 12 across - so you wind up with the 3 sectors only 1' apart at their bases. I wish you had some more ideas :-), but thanks for the thought and the time! Mac -- WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/
Re: [WISPA] 180* sector choices
Mac, Thanks for replying to my concerns and suggestions. Have you tried using 5 to 10 feet of vertical separation between the antennas rather than mounting them all at the same height? 10 feet of vertical separation should be enough to prevent one AP transmitter from overloading another AP receiver. Secondly, single-channel bandpass filters are available which will provide additional receiver protection from nearby transmitters operating on non-overlapping frequencies. Finally, higher-priced antennas normally have a higher front-to-back ratio which increases isolation (minimizes interaction) between the antennas. A minimum f/b ratio of 30 dBm is recommended. Keep in mind that without dealing with these antenna isolation issues, you will likely have the same problems using two 180* sector antennas as you have had using three 120* sector antennas. jack Mac Dearman wrote: See in line please Behalf of Jack Unger Mac, Before you discard the idea of using three 120* sectors are you absolutely certain that the separation issue is really due to the antennas not being far enough apart? Have you thoroughly looked at other reasons why there could be interference between three APs like: [Mac says:] Well Jack - I'd like to think that I have exhausted the other possibilities :-) but I am always willing to listen. 1. Using three cards on a single motherboard in one enclosure without sufficient shielding between them. [Mac says:] All of our sector arrays utilize 3 different enclosures with one radio to the enclosure and then I try to separate the enclosures (and antennas) as far as possible. 2. Using three APs that are configured on frequencies that are too close together and are interfering with each other? [Mac says:] Unless we deploy 4 90* sectors we use non overlapping channels (1, 6 11) I guess what I'm asking is (before you go spend money on antennas that may or may not solve the problem) what equipment are you currently using, how is it configured, and how far apart can you actually get three sector antennas on the 25G tower? jack [Mac says:] I have come to the conclusion that it is interference from the backplane of the antennas due to not having adequate separation from each other. These small towers (although 180') like Rohn 25G aren't but 12 across - so you wind up with the 3 sectors only 1' apart at their bases. I wish you had some more ideas :-), but thanks for the thought and the time! Mac -- Jack Unger ([EMAIL PROTECTED]) - President, Ask-Wi.Com, Inc. FCC License # PG-12-25133 Serving the Broadband Wireless Industry Since 1993 Author of the WISP Handbook - Deploying License-Free Wireless WANs True Vendor-Neutral Wireless Consulting-Training-Troubleshooting FCC Part 15 Certification for Manufacturers and Service Providers Phone (VoIP Over Broadband Wireless) 818-227-4220 www.ask-wi.com -- WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/
RE: [WISPA] 180* sector choices
Inline again :-) Behalf Of Jack Unger Mac, Thanks for replying to my concerns and suggestions. Have you tried using 5 to 10 feet of vertical separation between the antennas rather than mounting them all at the same height? 10 feet of vertical separation should be enough to prevent one AP transmitter from overloading another AP receiver. [Mac says:] Now you are talking the Jack Unger talk that makes me sit up and take notice :-) I have not tried the vertical separation because it looks so unprofessional (although is a professional move) to have 3 sectors spread out over thirty feet and it also puts 2 of my three sectors at a disadvantage due to the height loss. We cover a lot of rugged territory, conquer (really not very well) massive 90' Oak trees and connect subs as far as 20 miles off these towers. It is a fine idea and one I may have to move to! Secondly, single-channel bandpass filters are available which will provide additional receiver protection from nearby transmitters operating on non-overlapping frequencies. [Mac says:] That sounds like the way I will go. I appreciate the idea and suggestion. I don't know why I haven't thought of that before. I guess I have never bought or even had need of a bandpass filter till now. Well truth be known it seems I have needed them for years, but didn't realize it till today. Finally, higher-priced antennas normally have a higher front-to-back ratio which increases isolation (minimizes interaction) between the antennas. A minimum f/b ratio of 30 dBm is recommended. [Mac says:] We have always bought and used PacWireless antennas and thee 16.5dbi 120* VPOL sectors have at least a F/B ratio of 25db. I realize the more you spend the better F/B ratio you get and that is where my original thread started - - looking for some good sectors :-) Keep in mind that without dealing with these antenna isolation issues, you will likely have the same problems using two 180* sector antennas as you have had using three 120* sector antennas. [ [Mac says:] That is fine advice Jack and I appreciate the fine guidance. You have made me think - - and that may be a dangerous thing. Now - - let me go order some bandpass filters and hang them on one of these troubled tower to see what is gonna happen. I will post back here and let you know my results. Thanks again Jack!! Mac Dearman jack Mac Dearman wrote: See in line please Behalf of Jack Unger Mac, Before you discard the idea of using three 120* sectors are you absolutely certain that the separation issue is really due to the antennas not being far enough apart? Have you thoroughly looked at other reasons why there could be interference between three APs like: [Mac says:] Well Jack - I'd like to think that I have exhausted the other possibilities :-) but I am always willing to listen. 1. Using three cards on a single motherboard in one enclosure without sufficient shielding between them. [Mac says:] All of our sector arrays utilize 3 different enclosures with one radio to the enclosure and then I try to separate the enclosures (and antennas) as far as possible. 2. Using three APs that are configured on frequencies that are too close together and are interfering with each other? [Mac says:] Unless we deploy 4 90* sectors we use non overlapping channels (1, 6 11) I guess what I'm asking is (before you go spend money on antennas that may or may not solve the problem) what equipment are you currently using, how is it configured, and how far apart can you actually get three sector antennas on the 25G tower? jack [Mac says:] I have come to the conclusion that it is interference from the backplane of the antennas due to not having adequate separation from each other. These small towers (although 180') like Rohn 25G aren't but 12 across - so you wind up with the 3 sectors only 1' apart at their bases. I wish you had some more ideas :-), but thanks for the thought and the time! Mac -- Jack Unger ([EMAIL PROTECTED]) - President, Ask-Wi.Com, Inc. FCC License # PG-12-25133 Serving the Broadband Wireless Industry Since 1993 Author of the WISP Handbook - Deploying License-Free Wireless WANs True Vendor-Neutral Wireless Consulting-Training-Troubleshooting FCC Part 15 Certification for Manufacturers and Service Providers Phone (VoIP Over Broadband Wireless) 818-227-4220 www.ask-wi.com -- 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] 180* sector choices
I'll take one! How much ? -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Rick Harnish Sent: Friday, May 18, 2007 4:25 PM To: 'WISPA General List' Subject: RE: [WISPA] 180* sector choices Jack, While we are on this topic, look at the .pdf file and give me your comments on this all in one sector from Pac Wireless? Thanks, Rick Harnish President OnlyInternet Broadband Wireless, Inc. 260-827-2482 Founding Member of WISPA -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Jack Unger Sent: Friday, May 18, 2007 4:18 PM To: WISPA General List Subject: Re: [WISPA] 180* sector choices Mac, Thanks for replying to my concerns and suggestions. Have you tried using 5 to 10 feet of vertical separation between the antennas rather than mounting them all at the same height? 10 feet of vertical separation should be enough to prevent one AP transmitter from overloading another AP receiver. Secondly, single-channel bandpass filters are available which will provide additional receiver protection from nearby transmitters operating on non-overlapping frequencies. Finally, higher-priced antennas normally have a higher front-to-back ratio which increases isolation (minimizes interaction) between the antennas. A minimum f/b ratio of 30 dBm is recommended. Keep in mind that without dealing with these antenna isolation issues, you will likely have the same problems using two 180* sector antennas as you have had using three 120* sector antennas. jack Mac Dearman wrote: See in line please Behalf of Jack Unger Mac, Before you discard the idea of using three 120* sectors are you absolutely certain that the separation issue is really due to the antennas not being far enough apart? Have you thoroughly looked at other reasons why there could be interference between three APs like: [Mac says:] Well Jack - I'd like to think that I have exhausted the other possibilities :-) but I am always willing to listen. 1. Using three cards on a single motherboard in one enclosure without sufficient shielding between them. [Mac says:] All of our sector arrays utilize 3 different enclosures with one radio to the enclosure and then I try to separate the enclosures (and antennas) as far as possible. 2. Using three APs that are configured on frequencies that are too close together and are interfering with each other? [Mac says:] Unless we deploy 4 90* sectors we use non overlapping channels (1, 6 11) I guess what I'm asking is (before you go spend money on antennas that may or may not solve the problem) what equipment are you currently using, how is it configured, and how far apart can you actually get three sector antennas on the 25G tower? jack [Mac says:] I have come to the conclusion that it is interference from the backplane of the antennas due to not having adequate separation from each other. These small towers (although 180') like Rohn 25G aren't but 12 across - so you wind up with the 3 sectors only 1' apart at their bases. I wish you had some more ideas :-), but thanks for the thought and the time! Mac -- Jack Unger ([EMAIL PROTECTED]) - President, Ask-Wi.Com, Inc. FCC License # PG-12-25133 Serving the Broadband Wireless Industry Since 1993 Author of the WISP Handbook - Deploying License-Free Wireless WANs True Vendor-Neutral Wireless Consulting-Training-Troubleshooting FCC Part 15 Certification for Manufacturers and Service Providers Phone (VoIP Over Broadband Wireless) 818-227-4220 www.ask-wi.com -- 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] 180* sector choices
- Original Message - From: Mac Dearman [EMAIL PROTECTED] To: 'WISPA General List' wireless@wispa.org Sent: Friday, May 18, 2007 2:01 PM Subject: RE: [WISPA] 180* sector choices Inline again :-) Behalf Of Jack Unger Mac, Thanks for replying to my concerns and suggestions. Have you tried using 5 to 10 feet of vertical separation between the antennas rather than mounting them all at the same height? 10 feet of vertical separation should be enough to prevent one AP transmitter from overloading another AP receiver. [Mac says:] Now you are talking the Jack Unger talk that makes me sit up and take notice :-) I have not tried the vertical separation because it looks so unprofessional (although is a professional move) to have 3 sectors spread out over thirty feet and it also puts 2 of my three sectors at a disadvantage due to the height loss. We cover a lot of rugged territory, conquer (really not very well) massive 90' Oak trees and connect subs as far as 20 miles off these towers. It is a fine idea and one I may have to move to! I've got some that are within a few feet of each other. Also have some that are RIGHT behind others. We're having some problems at that site that sure act like interference. I'm pretty sure at least some of it is self inflicted. How much there's no good way to tell. They are all the higher end Maxrad sectors. I'm going to get long lmr600 runs (50/40 and 30') and make sure that the radios are all down at the ground where I can get to them with a ladder, and I'll make sure that the antennas are all 10' or more apart. We're going to rebuild two sites in this manner. Secondly, single-channel bandpass filters are available which will provide additional receiver protection from nearby transmitters operating on non-overlapping frequencies. [Mac says:] That sounds like the way I will go. I appreciate the idea and suggestion. I don't know why I haven't thought of that before. I guess I have never bought or even had need of a bandpass filter till now. Well truth be known it seems I have needed them for years, but didn't realize it till today. I don't use bandpass filters. I have to change channels far too often for that. I'm finding that some radios are far more effective in their isolation than others are. I'd also rather use antennas for my isolation than having another device I have to worry about inline. Finally, higher-priced antennas normally have a higher front-to-back ratio which increases isolation (minimizes interaction) between the antennas. A minimum f/b ratio of 30 dBm is recommended. [Mac says:] We have always bought and used PacWireless antennas and thee 16.5dbi 120* VPOL sectors have at least a F/B ratio of 25db. I realize the more you spend the better F/B ratio you get and that is where my original thread started - - looking for some good sectors :-) TilTek was brought up. Those are good. So are radio waves. I've been REALLY happy with the vpol ($425ish) and hpol ($250ish) Maxrad adjustable beam sectors. I like the flexibility for the future too. marlon Keep in mind that without dealing with these antenna isolation issues, you will likely have the same problems using two 180* sector antennas as you have had using three 120* sector antennas. [ [Mac says:] That is fine advice Jack and I appreciate the fine guidance. You have made me think - - and that may be a dangerous thing. Now - - let me go order some bandpass filters and hang them on one of these troubled tower to see what is gonna happen. I will post back here and let you know my results. Thanks again Jack!! Mac Dearman jack Mac Dearman wrote: See in line please Behalf of Jack Unger Mac, Before you discard the idea of using three 120* sectors are you absolutely certain that the separation issue is really due to the antennas not being far enough apart? Have you thoroughly looked at other reasons why there could be interference between three APs like: [Mac says:] Well Jack - I'd like to think that I have exhausted the other possibilities :-) but I am always willing to listen. 1. Using three cards on a single motherboard in one enclosure without sufficient shielding between them. [Mac says:] All of our sector arrays utilize 3 different enclosures with one radio to the enclosure and then I try to separate the enclosures (and antennas) as far as possible. 2. Using three APs that are configured on frequencies that are too close together and are interfering with each other? [Mac says:] Unless we deploy 4 90* sectors we use non overlapping channels (1, 6 11) I guess what I'm asking is (before you go spend money on antennas that may or may not solve the problem) what equipment are you currently using, how is it configured, and how far apart can you actually get three sector antennas on the 25G tower? jack [Mac says:] I have come to the conclusion that it is interference
Re: [WISPA] 180* sector choices
Rick, Here's what I see that's good about the Pac Wireless antenna: 1. The 3-in-1 design may be the only solution where only one antenna-mounting space exists on a tower. 2. The inclusion of electrical downtilt will minimize overshooting customers. 3. The inclusion of null fill will minimize connectivity problems with customers located very close to the tower. 4. The 15 dBi gain is in the appropriate and usable range. 5. The weight (14 lbs) will make the antenna easy to raise and mount. 6. The price range ($700) is moderate considering that you're really getting three sector antennas in one. Here's what I see that will need special consideration and planning. 1. The front-to-back ratio is only 15 dB. This is low compared to the 30 dB that I usually recommend for high-quality antennas. 2. The sector-to-sector isolation is 35 dB. When compared to the 83 dB of isolation that 10 feet of vertical separation would provide, 35 dB is a lot less. In summary, this appears to be a good antenna system with the one limitation that the somewhat low f/b ratio and sector-to-sector isolation will combine to place the burden for good AP-to-AP isolation on the quality of the co-located access point receivers and the quality of the overall AP/site design. Receivers with poor or moderate selectivity (in other words, receivers on Wi-Fi cards) will be overloaded by the other AP transmitters with the result being a throughput reduction that begins when traffic levels increase. The more traffic, the more missed incoming packets, the more retransmissions and the more throughput reduction. The result will be that the site reaches saturation sooner and won't handle as much traffic as a site where the AP receivers are not being overloaded. The solution (other than to use really expensive equipment which has good receiver filtering and selectivity built in) is to again use single-channel bandpass filters on each AP. These will reduce the level of signal from the co-located adjacent-channel AP transmitters and permit the site to handle more traffic (reach saturation later) than a site where the receivers ARE being overloaded. Finally, in addition to the above, it's important not to defeat the antenna isolation by letting RF energy leak directly from AP to AP either on the ground or from PC-card to PC card. Proper shielding and grounding will help to maintain that hard-won receiver-to-transmitter isolation resulting in a high-performance, high-traffic handling, reliable, profitable site. jack Rick Harnish wrote: Jack, While we are on this topic, look at the .pdf file and give me your comments on this all in one sector from Pac Wireless? Thanks, Rick Harnish President OnlyInternet Broadband Wireless, Inc. 260-827-2482 Founding Member of WISPA -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Jack Unger Sent: Friday, May 18, 2007 4:18 PM To: WISPA General List Subject: Re: [WISPA] 180* sector choices Mac, Thanks for replying to my concerns and suggestions. Have you tried using 5 to 10 feet of vertical separation between the antennas rather than mounting them all at the same height? 10 feet of vertical separation should be enough to prevent one AP transmitter from overloading another AP receiver. Secondly, single-channel bandpass filters are available which will provide additional receiver protection from nearby transmitters operating on non-overlapping frequencies. Finally, higher-priced antennas normally have a higher front-to-back ratio which increases isolation (minimizes interaction) between the antennas. A minimum f/b ratio of 30 dBm is recommended. Keep in mind that without dealing with these antenna isolation issues, you will likely have the same problems using two 180* sector antennas as you have had using three 120* sector antennas. jack Mac Dearman wrote: See in line please Behalf of Jack Unger Mac, Before you discard the idea of using three 120* sectors are you absolutely certain that the separation issue is really due to the antennas not being far enough apart? Have you thoroughly looked at other reasons why there could be interference between three APs like: [Mac says:] Well Jack - I'd like to think that I have exhausted the other possibilities :-) but I am always willing to listen. 1. Using three cards on a single motherboard in one enclosure without sufficient shielding between them. [Mac says:] All of our sector arrays utilize 3 different enclosures with one radio to the enclosure and then I try to separate the enclosures (and antennas) as far as possible. 2. Using three APs that are configured on frequencies that are too close together and are interfering with each other? [Mac says:] Unless we deploy 4 90* sectors we use non overlapping channels (1, 6 11) I guess what I'm asking is (before you go spend money on antennas that may or may not solve the problem) what
RE: [WISPA] 180* sector choices
That's a lot of sugar for less than a dollar Jack. I'd be willing to pay for that info! (Or buy you a round - or both) Thanks, Mac -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Jack Unger Sent: Friday, May 18, 2007 5:33 PM To: WISPA General List Subject: Re: [WISPA] 180* sector choices Rick, Here's what I see that's good about the Pac Wireless antenna: 1. The 3-in-1 design may be the only solution where only one antenna-mounting space exists on a tower. 2. The inclusion of electrical downtilt will minimize overshooting customers. 3. The inclusion of null fill will minimize connectivity problems with customers located very close to the tower. 4. The 15 dBi gain is in the appropriate and usable range. 5. The weight (14 lbs) will make the antenna easy to raise and mount. 6. The price range ($700) is moderate considering that you're really getting three sector antennas in one. Here's what I see that will need special consideration and planning. 1. The front-to-back ratio is only 15 dB. This is low compared to the 30 dB that I usually recommend for high-quality antennas. 2. The sector-to-sector isolation is 35 dB. When compared to the 83 dB of isolation that 10 feet of vertical separation would provide, 35 dB is a lot less. In summary, this appears to be a good antenna system with the one limitation that the somewhat low f/b ratio and sector-to-sector isolation will combine to place the burden for good AP-to-AP isolation on the quality of the co-located access point receivers and the quality of the overall AP/site design. Receivers with poor or moderate selectivity (in other words, receivers on Wi-Fi cards) will be overloaded by the other AP transmitters with the result being a throughput reduction that begins when traffic levels increase. The more traffic, the more missed incoming packets, the more retransmissions and the more throughput reduction. The result will be that the site reaches saturation sooner and won't handle as much traffic as a site where the AP receivers are not being overloaded. The solution (other than to use really expensive equipment which has good receiver filtering and selectivity built in) is to again use single-channel bandpass filters on each AP. These will reduce the level of signal from the co-located adjacent-channel AP transmitters and permit the site to handle more traffic (reach saturation later) than a site where the receivers ARE being overloaded. Finally, in addition to the above, it's important not to defeat the antenna isolation by letting RF energy leak directly from AP to AP either on the ground or from PC-card to PC card. Proper shielding and grounding will help to maintain that hard-won receiver-to-transmitter isolation resulting in a high-performance, high-traffic handling, reliable, profitable site. jack Rick Harnish wrote: Jack, While we are on this topic, look at the .pdf file and give me your comments on this all in one sector from Pac Wireless? Thanks, Rick Harnish President OnlyInternet Broadband Wireless, Inc. 260-827-2482 Founding Member of WISPA -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Jack Unger Sent: Friday, May 18, 2007 4:18 PM To: WISPA General List Subject: Re: [WISPA] 180* sector choices Mac, Thanks for replying to my concerns and suggestions. Have you tried using 5 to 10 feet of vertical separation between the antennas rather than mounting them all at the same height? 10 feet of vertical separation should be enough to prevent one AP transmitter from overloading another AP receiver. Secondly, single-channel bandpass filters are available which will provide additional receiver protection from nearby transmitters operating on non-overlapping frequencies. Finally, higher-priced antennas normally have a higher front-to-back ratio which increases isolation (minimizes interaction) between the antennas. A minimum f/b ratio of 30 dBm is recommended. Keep in mind that without dealing with these antenna isolation issues, you will likely have the same problems using two 180* sector antennas as you have had using three 120* sector antennas. jack Mac Dearman wrote: See in line please Behalf of Jack Unger Mac, Before you discard the idea of using three 120* sectors are you absolutely certain that the separation issue is really due to the antennas not being far enough apart? Have you thoroughly looked at other reasons why there could be interference between three APs like: [Mac says:] Well Jack - I'd like to think that I have exhausted the other possibilities :-) but I am always willing to listen. 1. Using three cards on a single motherboard in one enclosure without sufficient shielding between them. [Mac says:] All of our sector arrays utilize 3
Re: [WISPA] 180* sector choices
Jack, If one was to use 3 10MHz channels with 10MHz seperation between channels, they would see the same or better performance than 3 full size channels side by side. So thats my advice, but it won't be wifi. Would be nice if there was a 5 gig option per sector so that you could do 2 2 gig channels at 1 and 11 and a 5 gig sector. George Jack Unger wrote: Rick, Here's what I see that's good about the Pac Wireless antenna: 1. The 3-in-1 design may be the only solution where only one antenna-mounting space exists on a tower. 2. The inclusion of electrical downtilt will minimize overshooting customers. 3. The inclusion of null fill will minimize connectivity problems with customers located very close to the tower. 4. The 15 dBi gain is in the appropriate and usable range. 5. The weight (14 lbs) will make the antenna easy to raise and mount. 6. The price range ($700) is moderate considering that you're really getting three sector antennas in one. Here's what I see that will need special consideration and planning. 1. The front-to-back ratio is only 15 dB. This is low compared to the 30 dB that I usually recommend for high-quality antennas. 2. The sector-to-sector isolation is 35 dB. When compared to the 83 dB of isolation that 10 feet of vertical separation would provide, 35 dB is a lot less. In summary, this appears to be a good antenna system with the one limitation that the somewhat low f/b ratio and sector-to-sector isolation will combine to place the burden for good AP-to-AP isolation on the quality of the co-located access point receivers and the quality of the overall AP/site design. Receivers with poor or moderate selectivity (in other words, receivers on Wi-Fi cards) will be overloaded by the other AP transmitters with the result being a throughput reduction that begins when traffic levels increase. The more traffic, the more missed incoming packets, the more retransmissions and the more throughput reduction. The result will be that the site reaches saturation sooner and won't handle as much traffic as a site where the AP receivers are not being overloaded. The solution (other than to use really expensive equipment which has good receiver filtering and selectivity built in) is to again use single-channel bandpass filters on each AP. These will reduce the level of signal from the co-located adjacent-channel AP transmitters and permit the site to handle more traffic (reach saturation later) than a site where the receivers ARE being overloaded. Finally, in addition to the above, it's important not to defeat the antenna isolation by letting RF energy leak directly from AP to AP either on the ground or from PC-card to PC card. Proper shielding and grounding will help to maintain that hard-won receiver-to-transmitter isolation resulting in a high-performance, high-traffic handling, reliable, profitable site. jack Rick Harnish wrote: Jack, While we are on this topic, look at the .pdf file and give me your comments on this all in one sector from Pac Wireless? Thanks, Rick Harnish President OnlyInternet Broadband Wireless, Inc. 260-827-2482 Founding Member of WISPA -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Jack Unger Sent: Friday, May 18, 2007 4:18 PM To: WISPA General List Subject: Re: [WISPA] 180* sector choices Mac, Thanks for replying to my concerns and suggestions. Have you tried using 5 to 10 feet of vertical separation between the antennas rather than mounting them all at the same height? 10 feet of vertical separation should be enough to prevent one AP transmitter from overloading another AP receiver. Secondly, single-channel bandpass filters are available which will provide additional receiver protection from nearby transmitters operating on non-overlapping frequencies. Finally, higher-priced antennas normally have a higher front-to-back ratio which increases isolation (minimizes interaction) between the antennas. A minimum f/b ratio of 30 dBm is recommended. Keep in mind that without dealing with these antenna isolation issues, you will likely have the same problems using two 180* sector antennas as you have had using three 120* sector antennas. jack Mac Dearman wrote: See in line please Behalf of Jack Unger Mac, Before you discard the idea of using three 120* sectors are you absolutely certain that the separation issue is really due to the antennas not being far enough apart? Have you thoroughly looked at other reasons why there could be interference between three APs like: [Mac says:] Well Jack - I'd like to think that I have exhausted the other possibilities :-) but I am always willing to listen. 1. Using three cards on a single motherboard in one enclosure without sufficient shielding between them. [Mac says:] All of our sector arrays utilize 3 different enclosures with one radio to the enclosure and then I try to separate the enclosures
