Beamforming Basics
Think of radio transmitters as little stones dropped in a pool. You know from high school physics that a dropped object will send out waves across the water’s surface. If you drop two stones, those waves will overlap with each other in a regular “interference” pattern. Changing the characteristics of a stone will change the amplitude and phase of the waves it emits, as well as the characteristics of the interference pattern generated with waves from other stones.
If you have enough control over the situation, you can have a sensor at the edge of the pool looking for just the right wave pattern, and you can keep changing the stone characteristics until that exact pattern arrives at that particular point. Elsewhere in the pool, the wave pattern will be different, and that’s fine. You’re only looking for that one pattern in that one place. Everything else can be ignored.
In a nutshell, this is the essence of beamforming. You’re controlling the output characteristics of each transmitter within a transmitter array so that the overall signal is optimized to reach a given receiver in a given direction. With an antenna array in which each antenna is transmitting with slightly different characteristics, you have what’s called a phased array. As we’ll see, there are two primary forms of phased array used in wireless access points: on-chip and on-antenna, adopted by Cisco and Ruckus Wireless, respectively.
- beamforming ,
- wifi ,
- ruckus
first post?!?!?!
No, REAL first, dipshit.
I don't think it's a problem that this is really only enterprise-class hardware. The very fact that there's an tenna sensitivity that can cripple the entire system shows that for Joe Apefist this is too much trouble for its own worth.
But, the tech shows amazing potential and given some tweaking time, I'm sure it will become more robust and more economical and will rapidly see adoption at home.
Personally I can't wait!
As a crude guide if you want 10dB gain over omnidirectional (10x the power in some direction) then you need to have 10 antenae to cover all directions. It works but with an obvious price in money and size, and a more subtle one in intereference for/from other transmitters unlucky enough to be in the chosen direction.
Personally I'd prefer multiple omni basestations and just focus on minimising distance. Inverse square law is your friend.
Personally I'd prefer multiple omni basestations and just focus on minimising distance. Inverse square law is your friend.
:-)
Yeh totally why punch through 4 walls when you can punch through 2. Plus you can site access points/ repeaters in free space away from mwave reflective objects.
Also note that much more important to enterprise wireless LANs is NOT the raw AP to single client thoughput that so many of these gearhead tests do. We are constantly faced with offering stable and usable wifi for dozens to hundreds of concurrent users in crowded areas (conference centers, auditoriums....) Like any shared medium, Wifi suffers from co-channel interference and overly RF loud clients.
One BIG advantage that you will see enterprise vendors work towards is NOT how much speed to any one client you can get, but how much Reduced interference beamforming will allow to neighboring wireless APs in the same ESS. The net result is that all users see benefit of solid and stable wireless connectivity.