orthogon wrote: jewish_scientist wrote:
"Lets just give each car a unique radio channel," you may be naively saying. There are 3 reasons this is impossible. 1) AM radio gets a lot of noise in some situations. 2) FM radio signals disperse quickly. 3) There is an inherent limitation
on how much information can be sent through a medium; information refers to the signals from other cars AND internet/ smart-phone signals.
Not really. I presume that by (1) and (2) you actually mean radio waves in the MF and VHF bands respectively; AM and FM refer to the modulation techniques and these have no bearing on the propagation.
Oh, I did not realize that. I assumed that since we identify those radio signals by modulation techniques, the advantages and disadvantages were due to the modulation.
I couldn't bring myself to watch that video to the end, but it's pretty annoying.
In my opinion, that is actually one of the best shows on YouTube, but I see why you would find it annoying without context. The show is made by people in the gaming industry about the gaming industry. When they say "no one", they mean no one in the gaming industry. Developers could start work on a project assuming that by the time they were done the average player would have more bandwidth. Since the invention of online video games this has been true. For them to suddenly learn that bandwidth is inherently limited and going to run out is like Apple suddenly learning that some professor proved Moore's Law would end in 2020. I think what they found particularly annoying is that no one told them about this issue until it started having practical effects on their work; "It [this episode] is about a problem we did not even know existed until James ran head-long into it on a consulting gig."
In any case, communications over a short range, as in the car-to-car example, are a much easier problem, since it's possible to use high frequencies (e.g. 10s of GHz) which are attenuated very rapidly with distance.
Now knowing that frequency, not modulation, is what gives radio signals their properties, I will concede that car-to-car communication is possible. Still, that only helps reduce traffic, not eliminate it entirely. There really is no way to get around the fact that roads are used by things besides cars (bikes, pedestrians, animals, motorcycles*).
bits per second per Hertz per square kilometre
a/b/c = a/bc, so shouldn't that unit be bits per second Hertz kilometer^2, and are you sure that 1/Hertz and 1/second do not cancel each other become cycle instead.
*Self driving motorcycles will never exist, because the rider shifts their weight
to keep the bike stable while it turns.