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With enough beamforming there's spectrum. If I option-click the wifi icon on my laptop, it says "NSS 2" -- that is, the Number of Spatial Streams is 2. My lapt
by jjoonathan 3y ago
With enough beamforming there's spectrum.
If I option-click the wifi icon on my laptop, it says "NSS 2" -- that is, the Number of Spatial Streams is 2. My laptop and router have identified two different spatial paths between them and are using their multiple antennae to send different data down the different paths.. NSS=2 is the limit for my router because it only has 2 antenna, but those routers with a ring of antennae that look like they were designed by the Dark Lord Sauron to top a tower in Mordor can fire correspondingly more simultaneous spatial streams. Cell towers with antenna arrays can do even better.
There is plenty of spectrum, just not for old single-antenna tech.
- gruez 3y ago>If I option-click the wifi icon on my laptop, it says "NSS 2" -- that is, the Number of Spatial Streams is 2. My laptop and router have identified two different spatial paths between them and are using their multiple antennae to send different data down the different paths.. Doesn't that use 2x the spectrum? If so that doesn't really solve the problem. Sure, you're getting 2x the speeds, but also using the 2x the spectrum which is still a shared resource.
- jjoonathan 3y agoEmphatically not. Every chunk of space, propagation direction, and polarization has its own spectrum. Draw a box, count the photons. If you point a satellite dish at different satellites, you see different signals, even if the frequencies are the same. The same trick works for "virtual antennas" built out of phased arrays of real antennas, except you can steer them in microseconds and without any motors. MIMO leverages this.