There is also something called Shannon's Theorem http://en.wikipedia.org/wiki/Shannon%E2%80%93Hartley_theorem
For wireless, there is no Moore's law, it comes down to 3 things, C ~= 1.4 * B*S/N which basically says that information rate is proportional to bandwidth (which in this context means RF spectrum) times SINR (signal to interference and noise ratio). The fact is that there is a limited amount of spectrum available so the only way to get an order of magnitude more throughput (which is what is needed to call something 5G, that is no marketing hype). So the only way to do that is to move the cell towers closer to the user to increase the SINR. That is very difficult and expensive. So be wary of 5G claims, 4G-LTE already comes close to the Shannon limit now, to get more throughput requires a ton more cell towers, probably an uneconomical amount.