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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. From a wikipedia

> 2. Cell tower antennas are simple dipoles, not directional antennas. This is where you went wrong. They are in fact directional antennas. From a wikipedia article: "Due to the sectorized arrangement of antennas on a tower, it is possible to vary the strength and angle of each sector depending on the coverage of other towers in view of the sector." http://en.wikipedia.org/wiki/Cell_site#Channel_reuse http://en.wikipedia.org/wiki/Cell_site#Channel_reuse That certainly sounds to me like a cell base station not only already has multiple antennas (which you can see with your own eyes) but that it makes use of said multiple antennas in some kind of semi-intelligent way. Obviously not as smart as the pCell, but sorta. > For a beam width of 30 degrees, you would need 12 antennas where one exists now, and you would need a way to switch between antennas on each transmitted packet to multiple served devices. That would be a nightmare. As we've established there are already multiple antennas. Maybe not 12, but several. And this is a trivial problem to solve actually. The same technology that tracks you from mast to mast can be used to track you from antenna to antenna. This is the job of the base station controller. Here's a clip: "By using directional antennas on a base station, each pointing in different directions, it is possible to sectorise the base station so that several different cells are served from the same location. Typically these directional antennas have a beamwidth of 65 to 85 degrees. This increases the traffic capacity of the base station (each frequency can carry eight voice channels) whilst not greatly increasing the interference caused to neighboring cells (in any given direction, only a small number of frequencies are being broadcast). Typically two antennas are used per sector, at spacing of ten or more wavelengths apart. This allows the operator to overcome the effects of fading due to physical phenomena such as multipath reception. Some amplification of the received signal as it leaves the antenna is often used to preserve the balance between uplink and downlink signal." http://en.wikipedia.org/wiki/Base_station_controller#Sectorization http://en.wikipedia.org/wiki/Base_station_controller#Sectori... I appreciate your enthusiasm for debate but please do some more research into cellular radio before you weigh in further. You've got a lot of the basic concepts right but not the particulars of the implementation. If that comes across harsh; I'm sorry. I don't know how to communicate this more gently.

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...

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...