To fill the gap between those growth rates, governments and industry agree that what's needed is at least a two-pronged approach, with more spectrum as well as strategies to make better use of the spectrum that's already available. Carriers also are taking steps that should help to dampen the growth in demand.

Here is an overview of some of the techniques that may help to stave off a mobile crunch. They fall into three main categories: getting more out of service providers' current mobile data spectrum, making better use of all possible mobile frequencies, and reducing the demand on spectrum assigned to mobile services.

1. Small cells

Mobile operators can serve more subscribers and give them better performance using the very same spectrum they already have. One way to do this is by installing smaller cells to supplement the traditional "macro" cells that cover an entire neighborhood. As long as the two types of cells don't interfere with each other, subscribers' mobile devices can connect to a small cell serving a street corner or an office and share it only with the other subscribers nearby. If there are enough small cells in the area, users can be handed off from one to the other without ever taxing the macro cell, which remains available for subscribers who aren't near to an area of small cells.