That is correct.
However the lowest GSM frequency was 300Mhz, so there is still quite a lot of bandwidth there (if I’m not mistaken to a theoretical maximum of 600Mbit/s for a 2 level signal, though in practice quite a lot less as this are radio-waves rather than signals in circuit lines, so encoding schemes have to be disgned for a lot more noise and other problems).
Anyways, the point being that the right encoding scheme can extract some Mbit/s from even the 300Mhz band.
zaphod@feddit.de 8 months ago
Frequency isn’t that relevant, it’s frequency bandwidth. The bit rate is n/T with n being bits per symbol and T symbol duration which itself is 1/B with B being the frequency bandwidth. You want to increase the bit rate you can either increase the number of bits per symbol or increase the frequency bandwith. 5G allows bandwiths up to 400MHz per channel, there isn’t enough space in the lower frequency ranges for such large bandwidths, so you go up.