While trying to increase the speed of my internet, I just realized how Bandwidth is understood differently in the networking world. That makes me kind of confused with why increasing a Wifi Bandwidth from 20MHz to 40MHz increases speed, as people always say (provided no neighboring networks). It could be wrong but my first impression is that the signal CAN be sent two times faster, but not necessary. It just has the potential to use the upper half of the Bandwidth. Right? I don't get it. I know why FM and square wave needs more bandwidth in signals and systems though.
Can someone please explain to me how "physically" speed increases? Why more data is sent with wider bandwidth? Please no classic water pipe or highway analogy cause I am not even sure how the water is even behaving or how water is being pumped... Or should the analogy be more "high speed" lanes are available?
BTW is channel 11 theoretically faster than channel 1? Since the frequency is SLIGHTLY higher...?