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.
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.