Verizon Wireless increased its ability improve its network speeds and capacity, after the U.S. Justice Department approved a controversial spectrum purchase from several major cable companies today.

As data usage on mobile networks explodes with more people using smartphone and tablet devices, wireless carriers are fiercely competing to relieve congestion while at the same time trying to deliver (and advertise) ever-faster service. "It is a precious commodity," Bill Moore, CEO of Root Metrics, a company that measures the performance of carrier networks, says. Verizon announced that its 4G LTE network will cover more than 75 percent of the U.S. population as it expands in dozens of markets this week.

It will be interesting to see what Verizon does with the new spectrum it's purchased. It could either chose to use it to provide headroom to relieve data congestion on existing networks, or be reserved for future services, Moore explained.