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>> 2. Cell tower antennas are simple dipoles, not directional antennas. > This is where you went wrong. They are in fact directional antennas. No, they (simpl

by lutusp 13y ago

>> 2. Cell tower antennas are simple dipoles, not directional antennas. > This is where you went wrong. They are in fact directional antennas. No, they (simple dipoles) are not. Read my quote above -- a simple dipole is not directional. Your reply says that an array of such dipoles can be made directional, which is true and a point I made as well, but it's a different topic. > I appreciate your enthusiasm for debate but please do some more research into cellular radio before you weigh in further. That's my advice to you -- before you change the subject, learn enough to realize that you're changing the subject. > If that comes across harsh Harsh? How about wrong? Dipoles are not directional. Cell tower antennas are vertically polarized dipoles, therefore they aren't directional. An array of dipoles is directional in a crude sense and as expressed in your linked article, but not remotely comparable to a phased array, the topic of the present discussion. > I don't know how to communicate this more gently. Let's see if you gently recognize your error. If you move the goal posts, obviously the game changes.

msandford 13y ago
Okay I can't tell if you're trolling me or what. Let's start with one really simple thing and from that we can learn a lot. You have claimed repeatedly that cell tower antennas are simple dipoles. What do you base this claim upon? And when I say "base" I'd really like some links to in-depth explanations. I don't want to see a simple hexagonal cell system like this with A-G labeled cells and a repeating pattern (http://www.ofcom.org.uk/static/archive/ra/topics/mpsafety/school-audit/mobilework.htm http://www.ofcom.org.uk/static/archive/ra/topics/mpsafety/sc...). That's how cell phones got started back when there weren't many users and there was a LOT of ground to cover. These days there are many, many more users and as such things have gotten more sophisticated. I included links to wikipedia articles that contain more current information. If you can prove that they are in fact simple dipoles I have no problems accepting that they are not directional; a simple dipole is an omni. You learn that as a 3rd year EE.
- lutusp 13y ago
  > You have claimed repeatedly that cell tower antennas are simple dipoles. What do you base this claim upon? The fact that the vast majority of cell tower antennas are simple dipoles -- it's the basis of the system. You want to argue -- go somewhere else. I was doing this before you were born. http://www.unisonsite.com/pdf/resource-center/How%20Towers%20Work.pdf http://www.unisonsite.com/pdf/resource-center/How%20Towers%2... > I don't want to see a simple hexagonal cell system ... No, of course not -- that would imply that you were wrong. This discussion revolves around a scheme to phase ordinary cellular antennas to improve the performance of a classic cellular system, the kind of system you don't want to talk about. The big advantage of the scheme under discussion is that it works with a classic cellular antenna system (plus some additional electronics and mathematical processing). That makes a classic cellular system the topic. Typical collection of vertically polarized cellular dipole transmitting and receiving antennas: http://upload.wikimedia.org/wikipedia/commons/2/2d/Cell_Phone_Tower.jpg http://upload.wikimedia.org/wikipedia/commons/2/2d/Cell_Phon...
  - msandford 13y ago
    In the first document you linked here's an excerpt: "Wireless carriers have taken the reduce and reuse approach a step further with the use of directional antennas, illustrated in Figure 5. Rather than using a single omni-directional antenna that covers a circular radius around a tower, carriers introduced directional antennas, to further segment cell sizes and enable the reuse of additional frequencies. For example, placing three antennas operating in separate frequencies on a tower allows sectors to be created within a cell, essentially tripling capacity per cell." And a clip from a wikipedia page (http://en.wikipedia.org/wiki/Cellular_network#Directional_antennas http://en.wikipedia.org/wiki/Cellular_network#Directional_an...): "Cell towers frequently use a directional signal to improve reception in higher traffic areas. In the United States, the FCC limits omni-directional cell tower signals to 100 watts of power. If the tower has directional antennas, the FCC allows the cell operator to broadcast up to 500 watts of effective radiated power (ERP).[7]" Furthermore here is a diagram of how this is done: http://en.wikipedia.org/wiki/File:CellTowersAtCorners.gif http://en.wikipedia.org/wiki/File:CellTowersAtCorners.gif The picture that you linked to on the wikimedia site shows what are clearly referred to by another wikipedia page as "sector antennas". See for yourself. http://en.wikipedia.org/wiki/Sector_antenna http://en.wikipedia.org/wiki/Sector_antenna Here's what a single one looks like: http://en.wikipedia.org/wiki/File:Sector_antenna2.png http://en.wikipedia.org/wiki/File:Sector_antenna2.png And here's what many of them at the top of a tower look like: http://en.wikipedia.org/wiki/File:Transmitting_tower_top_us.jpg http://en.wikipedia.org/wiki/File:Transmitting_tower_top_us.... Compare those with the picture that you linked which you claim is of simple dipoles. I see very little difference between the two. Which is more likely? That they're making dipoles which just happen to look exactly like sector antennas AND that they're putting up well more than they need to (since dipoles are omni they'd only need one) or they're actually sector antennas? Finally if you're going to invoke the "I was doing this before you were born" I'm more than happy to quit now. I had this foolish idea that you (as most people on HN do) wanted to understand the world as it really is. I see now that I was mistaken, you simply want to be right. That's fine, I can't fault you for it. It's human nature. But please take that kind of corrosive attitude elsewhere. The reason this community is so great is that people here listen to data or evidence. Please don't dilute those values for the sake of "winning" a stupid internet argument.
- stox 13y ago
  A dipole is not directional? The radiation pattern of a resonant dipole consists of toroidal lobes normal the to axis of the dipole with nulls at the axis of the dipole. Source: I do NEC simulations of my antennas for amateur radio.
  - lutusp 13y ago
    > A dipole is not directional? A vertical dipole, something I mentioned a few posts ago, before msandford decided to turn this into a pissing contest. As a radio amateur, you will be familiar with the radiation pattern of a 1/4 wave vertical coupled to a ground plane.

by lutusp 13y ago

msandford 13y ago

Okay I can't tell if you're trolling me or what. Let's start with one really simple thing and from that we can learn a lot. You have claimed repeatedly that cell tower antennas are simple dipoles. What do you base this claim upon? And when I say "base" I'd really like some links to in-depth explanations. I don't want to see a simple hexagonal cell system like this with A-G labeled cells and a repeating pattern (http://www.ofcom.org.uk/static/archive/ra/topics/mpsafety/school-audit/mobilework.htm http://www.ofcom.org.uk/static/archive/ra/topics/mpsafety/sc...). That's how cell phones got started back when there weren't many users and there was a LOT of ground to cover. These days there are many, many more users and as such things have gotten more sophisticated. I included links to wikipedia articles that contain more current information. If you can prove that they are in fact simple dipoles I have no problems accepting that they are not directional; a simple dipole is an omni. You learn that as a 3rd year EE.

lutusp 13y ago
> You have claimed repeatedly that cell tower antennas are simple dipoles. What do you base this claim upon? The fact that the vast majority of cell tower antennas are simple dipoles -- it's the basis of the system. You want to argue -- go somewhere else. I was doing this before you were born. http://www.unisonsite.com/pdf/resource-center/How%20Towers%20Work.pdf http://www.unisonsite.com/pdf/resource-center/How%20Towers%2... > I don't want to see a simple hexagonal cell system ... No, of course not -- that would imply that you were wrong. This discussion revolves around a scheme to phase ordinary cellular antennas to improve the performance of a classic cellular system, the kind of system you don't want to talk about. The big advantage of the scheme under discussion is that it works with a classic cellular antenna system (plus some additional electronics and mathematical processing). That makes a classic cellular system the topic. Typical collection of vertically polarized cellular dipole transmitting and receiving antennas: http://upload.wikimedia.org/wikipedia/commons/2/2d/Cell_Phone_Tower.jpg http://upload.wikimedia.org/wikipedia/commons/2/2d/Cell_Phon...
- msandford 13y ago
  In the first document you linked here's an excerpt: "Wireless carriers have taken the reduce and reuse approach a step further with the use of directional antennas, illustrated in Figure 5. Rather than using a single omni-directional antenna that covers a circular radius around a tower, carriers introduced directional antennas, to further segment cell sizes and enable the reuse of additional frequencies. For example, placing three antennas operating in separate frequencies on a tower allows sectors to be created within a cell, essentially tripling capacity per cell." And a clip from a wikipedia page (http://en.wikipedia.org/wiki/Cellular_network#Directional_antennas http://en.wikipedia.org/wiki/Cellular_network#Directional_an...): "Cell towers frequently use a directional signal to improve reception in higher traffic areas. In the United States, the FCC limits omni-directional cell tower signals to 100 watts of power. If the tower has directional antennas, the FCC allows the cell operator to broadcast up to 500 watts of effective radiated power (ERP).[7]" Furthermore here is a diagram of how this is done: http://en.wikipedia.org/wiki/File:CellTowersAtCorners.gif http://en.wikipedia.org/wiki/File:CellTowersAtCorners.gif The picture that you linked to on the wikimedia site shows what are clearly referred to by another wikipedia page as "sector antennas". See for yourself. http://en.wikipedia.org/wiki/Sector_antenna http://en.wikipedia.org/wiki/Sector_antenna Here's what a single one looks like: http://en.wikipedia.org/wiki/File:Sector_antenna2.png http://en.wikipedia.org/wiki/File:Sector_antenna2.png And here's what many of them at the top of a tower look like: http://en.wikipedia.org/wiki/File:Transmitting_tower_top_us.jpg http://en.wikipedia.org/wiki/File:Transmitting_tower_top_us.... Compare those with the picture that you linked which you claim is of simple dipoles. I see very little difference between the two. Which is more likely? That they're making dipoles which just happen to look exactly like sector antennas AND that they're putting up well more than they need to (since dipoles are omni they'd only need one) or they're actually sector antennas? Finally if you're going to invoke the "I was doing this before you were born" I'm more than happy to quit now. I had this foolish idea that you (as most people on HN do) wanted to understand the world as it really is. I see now that I was mistaken, you simply want to be right. That's fine, I can't fault you for it. It's human nature. But please take that kind of corrosive attitude elsewhere. The reason this community is so great is that people here listen to data or evidence. Please don't dilute those values for the sake of "winning" a stupid internet argument.
stox 13y ago
A dipole is not directional? The radiation pattern of a resonant dipole consists of toroidal lobes normal the to axis of the dipole with nulls at the axis of the dipole. Source: I do NEC simulations of my antennas for amateur radio.
- lutusp 13y ago
  > A dipole is not directional? A vertical dipole, something I mentioned a few posts ago, before msandford decided to turn this into a pissing contest. As a radio amateur, you will be familiar with the radiation pattern of a 1/4 wave vertical coupled to a ground plane.