4 ms·
Exactly, high absorption creates the localized cells each of which is typically limited in the number of (transmitting) devices. For something like this long ra
by kurthr 3y ago
Exactly, high absorption creates the localized cells each of which is typically limited in the number of (transmitting) devices. For something like this long range IoT cell to work you would want to create temporal cells or limit them to very low power. The problem is that those require agreement between devices (and noise sources) while simple absorption doesn't (treats everything equally).
- anonymouskimmer 3y agoWould dynamic directional RADAR be feasible? Or would overlapping RADAR signals going in different directions interfere with each other?
- Namidairo 3y agoGiven the passive radar code in KrakenSDR apparently fell afoul of ITAR, one would have to be careful around this.
- kurthr 3y agoSome routers do have 3/4/5 antenna directional antenna systems. I'm not sure if there's enough room or cost margin for an IoT device. If they were only directional then, I'm not sure they would help all that much, if there were other devices in the same direction (within 3km). However, there might be very short range differential (eg quadrapole) that could have faster than r^2 fall-off. The problem is that you're relying on all other devices in-band to do the same. I think that's one of the reasons why unlicensed (ISM in the case of WiFi) spectrum is best used where the natural cell size (due to attenuation) is small.