Depends on your definition of cheap. Where the average yearly income is less than $2000 a year the build out costs of a tower network can be so astronomical that it's not possible to recoup the investment and at the same time offer affordable service at the rates the average citizen can afford. The major costs in this equation are the equipment and what makes that equipment expensive is the software IP behind it all and the astronomic amounts charged for the back-end equipment that runs the network. Costs that are almost entirely software as the physical hardware is quite cheap.
The kicker is that even when the patents expire, or in countries where they aren't valid the closed ecosystem prevents operators from offering service at locally affordable rates without paying the IP tax. The ultimate goal (at least from my perspective) of all these FOSS GSM projects is to break open the closed ecosystem and crack the security that enforces it so that software isn't an expense in the equation. This relegates the costs to construction, towers, power and general purpose equipment with FOSS on top. Without the "software" costs the systems can be erected cheaper, maybe even to the point where people making less than $2000 a year can afford service. At the least it's definitely going to lower the break point where more people can afford cellular service. Even if it takes 5 years or more to crack open, GSM is going to have a long lifespan in areas with low average incomes.
Most people in the west don't realize it, but cellular phones are the primary means of access to information in large areas of the world. Not just voice, but the primary internet access as well. These efforts to crack this closed ecosystem and the security that enforces it are vital to free access to information.
Harold's role in this is critical as the security is a key component to building a cellular service. Not only that but the benefits to those of us in the west as he could find security holes that right now only the government and criminals are aware of.