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It's not terribly difficult provided that you've got enough directional antennas in your base station. If you do, then every receiver is independent. In other

It's not terribly difficult provided that you've got enough directional antennas in your base station. If you do, then every receiver is independent. In other words it could very well scale as O(n), n = the number of devices.

lutusp 13y ago
> It's not terribly difficult provided that you've got enough directional antennas in your base station. This scheme doesn't rely on directional antennas, it relies on computing an optimal set of phase solutions for multiple antennas to maximize reception quality. Each antenna is an ordinary omnidirectional dipole, but several of them working together, with calculated phase delays, provide a kind of directionality if you want to think about it that way.
- msandford 13y ago
  How do you know it doesn't rely on directional antennas in addition to the multi-phase solution? If I were trying to do something like this I would ABSOLUTELY use multiple directional antennas in each base station AND phase things appropriately. I don't mean trying to make a ball of yagis or other narrow beam antennas. But at the very least try and take advantage of splitting a base station into multiple (2, 4, 8, etc) slices. I can't see how that would hurt performance (though it would probably make things more expensive) and it would certainly make it easier to get more bandwidth. Here's an excerpt from the patent: [0120]FIG. 3 provides additional detail of one embodiment of the Base Station 200 and Client Devices 203-207 shown in FIG. 2. For the purposes of simplicity, the Base Station 300 is shown with only three antennas 305 and only three Client Devices 306-308. It will be noted, however, that the embodiments of the invention described herein may be implemented with a virtually unlimited number of antennas 305 (i.e., limited only by available space and noise) and Client Devices 306-308. Obviously I haven't studied the patent in detail but that does sound to me like there are multiple antennas per base station.
  - lutusp 13y ago
    > How do you know it doesn't rely on directional antennas in addition to the multi-phase solution? Because: 1. The article claims it can use the existing cell tower system. 2. Cell tower antennas are simple dipoles, not directional antennas. > If I were trying to do something like this I would ABSOLUTELY use multiple directional antennas in each base station AND phase things appropriately. Yes, that would improve the performance, but this would make it a hard sell to cell companies who are trying to reduce the cost of their installed equipment. Also, to use directional antennas in a high-speed dynamic network, for a given beam width N, you would need 360/N directional antennas. 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. > Obviously I haven't studied the patent in detail but that does sound to me like there are multiple antennas per base station. Yes, the basic idea requires multiple antennas whose relative phase can be adjusted. But not directional antennas.
    - msandford 13y ago
      > 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.
cma 13y ago
Directional antennas is the main technique today, this guy isn't proposing a move from single to directional antennas.
- msandford 13y ago
  Right, I couldn't agree more. It's a very clever delay system that ensures that the EM waves all arrive at a single point such that they constructively add together. That means that when you're in the pCell pocket you get excellent reception because of everything adding together, and when you move away it drops off VERY quickly. It's smart stuff but not impossible to comprehend. I'm surprised that none of the VCs "experts" could figure it out.

lutusp 13y ago

> It's not terribly difficult provided that you've got enough directional antennas in your base station. This scheme doesn't rely on directional antennas, it relies on computing an optimal set of phase solutions for multiple antennas to maximize reception quality. Each antenna is an ordinary omnidirectional dipole, but several of them working together, with calculated phase delays, provide a kind of directionality if you want to think about it that way.

msandford 13y ago
How do you know it doesn't rely on directional antennas in addition to the multi-phase solution? If I were trying to do something like this I would ABSOLUTELY use multiple directional antennas in each base station AND phase things appropriately. I don't mean trying to make a ball of yagis or other narrow beam antennas. But at the very least try and take advantage of splitting a base station into multiple (2, 4, 8, etc) slices. I can't see how that would hurt performance (though it would probably make things more expensive) and it would certainly make it easier to get more bandwidth. Here's an excerpt from the patent: [0120]FIG. 3 provides additional detail of one embodiment of the Base Station 200 and Client Devices 203-207 shown in FIG. 2. For the purposes of simplicity, the Base Station 300 is shown with only three antennas 305 and only three Client Devices 306-308. It will be noted, however, that the embodiments of the invention described herein may be implemented with a virtually unlimited number of antennas 305 (i.e., limited only by available space and noise) and Client Devices 306-308. Obviously I haven't studied the patent in detail but that does sound to me like there are multiple antennas per base station.
- lutusp 13y ago
  > How do you know it doesn't rely on directional antennas in addition to the multi-phase solution? Because: 1. The article claims it can use the existing cell tower system. 2. Cell tower antennas are simple dipoles, not directional antennas. > If I were trying to do something like this I would ABSOLUTELY use multiple directional antennas in each base station AND phase things appropriately. Yes, that would improve the performance, but this would make it a hard sell to cell companies who are trying to reduce the cost of their installed equipment. Also, to use directional antennas in a high-speed dynamic network, for a given beam width N, you would need 360/N directional antennas. 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. > Obviously I haven't studied the patent in detail but that does sound to me like there are multiple antennas per base station. Yes, the basic idea requires multiple antennas whose relative phase can be adjusted. But not directional antennas.
  - msandford 13y ago
    > 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.

cma 13y ago

Directional antennas is the main technique today, this guy isn't proposing a move from single to directional antennas.

msandford 13y ago
Right, I couldn't agree more. It's a very clever delay system that ensures that the EM waves all arrive at a single point such that they constructively add together. That means that when you're in the pCell pocket you get excellent reception because of everything adding together, and when you move away it drops off VERY quickly. It's smart stuff but not impossible to comprehend. I'm surprised that none of the VCs "experts" could figure it out.