The Defense Department is building a 4G network based on Long-Term Evolution technology to ensure that the military branches can securely talk to one another, the chairman of the U.S. Joint Chiefs of Staff disclosed Thursday. Army Gen. Martin Dempsey said the Pentagon needs the system to consolidate 15,000 networks in the cloud. In a speech, Dempsey held up a phone that could run on the network. "This phone would make both Batman and James Bond jealous. With tools like this, the smartphone generation joining our military will help us pioneer a new era of mobile command and control," he said.