I came across an interesting innovation in the telecom sector recently and I just found a detailed article about it. It is difficult to imagine, but voice communication standards were established as early as in 1937 for landline networks and nothing changed since then. Frequencies ranged from 300 to 3400 Hz. When mobile networks were created old rules were adapted and new codecs helped to economize available frequencies. CDs give you as much as 44100 Hz. Do you feel the difference with the 3400 Hz limit for mobile and landline phones?
