Antenna’s that can control their own beam shape, what?!? Control the beam on demand? How can that be? Beamforming is a little more complicated than that. First, a quick, high level, history lesson. I don’t know how familiar you are with antennas, but they must be installed correctly. You could physically tilt the antenna a … Continue reading What is Beamforming? →
Antenna’s that can control their own beam shape, what?!? Control the beam on demand? How can that be? Beamforming is a little more complicated than that.
First, a quick, high level, history lesson.
I don’t know how familiar you are with antennas, but they must be installed correctly. You could physically tilt the antenna a few degrees to match your coverage. It’s like azimuth, that must be appropriately aligned for coverage. Older antennas were installed with a set “up tilt” or “down tilt.” They were fixed in tilt and azimuth. So, what they saw is what they heard, based on the antennas fixed pattern. The antenna pattern would determine what the antenna could hear and talk to. That was it, very simple. I know, there is gain, but for the sake of argument, let’s say they would talk to UE devices in their specific coverage area.
Then there was evolution! There were new ways to control tilt. CommScope had RET, Remote Electrical Tilt, for this purpose. I think it was a good idea, but it’s still a physical system. Basically, if I understand this, it’s an actuator that can change adjust the tilt + or – 3 or more degrees. However, it opened options to the end-user, the carriers, where they did not need a tower crew to adjust the tilt. Pretty cool!
How does it work?
Now a new type of evolution, beamforming!
With beamforming, none of the physical alignment goes away; we still need the proper tilt and azimuth to get started. Beamforming is done by very smart antennas, but the carriers did not have the corner on this technology. As a matter of fact, the Wi-Fi vendors have made significant advances in this technology. They did a great job getting 802.11 to do this. The BTS controls the beam from there so that the antenna can do its thing. Again, they all must work together to make this happen.
Where did this idea come from? Don’t let the carriers or OEMs fool you; it came from Wi-Fi. In fact, I believe one of the pioneers in beamforming was Ruckus! That’s right, the carrier-grade Wi-Fi OEM. Also, I must give credit to Linksys for putting the technology in their home Wi-Fi routers. Awesome! Thank you to Network World for making a video on this, (link is below in “Learn More” section).
Massive MIMO puts that on steroids. It takes the signal, both ways, and focuses on a user. If you have 64 by 64, then, in theory, you can focus on 64 individual users on that antenna. The idea is to hear users you want to hear at any moment. This allows the radio to talk to specific users simultaneously without sharing precious spectrum. How can they focus? Beamforming is how they do it. They employ a technique called 3D beamforming that dimensions the signal from that element in 3D, 3 dimensions. Beamforming will focus the beam on the specific user.
Now the carriers are asking the OEMs to take it to the next level. It is the cornerstone of making massive MIMO even more useful.
You see, massive MIMO relies on the beamforming technology to make it more efficient and push even more bandwidth through it! It is a crucial factor, like carrier aggregation. It all has to work together.
Now, by controlling the beam to match the user’s antenna, it becomes more efficient in several ways. Signal strength helps, but now the spectrum stream can be dedicated to that specific user the duration of the conversation. Not only the best signal possible but a dedicated conversation with that unit for a limited t...
