1-Gbps LTE? Yes, But You Need 40 MHz of Bandwidth

There is a simple answer to the question of why mobile service providers and would-be providers want more spectrum. As usage continues to climb, and as access speeds continue to climb, there is little chance of boosting access speeds, in the mobile or fixed wireless realms, without adding more spectrum.

For example, it is possible to deliver 1-Gbps mobile Internet access using Long Term Evolution, but that requires a 40-MHz block of spectrum, not the 10 MHz or 20 MHz channels now used by LTE providers.

Numerical superiority: LTE Advanced vs LTE
Source: 3GPP