On Friday, President Barack Obama issued an executive order on the "Assignment of National Security and Emergency Preparedness Communications Functions" because the "the Federal Government must have the ability to communicate at all times and under all circumstances to carry out its most critical and time sensitive missions."

Section 5.2 states that Secretary of Homeland Security shall "satisfy priority communications requirements through the use of commercial, Government, and privately owned communications resources, when appropriate." 

Furthermore, the Secretary of Homeland Security must "maintain a joint industry-Government center that is capable of assisting in the initiation, coordination, restoration, and reconstitution of NS/EP [National Security and Emergency Preparedness] communications services or facilities under all conditions of emerging threats, crisis, or emergency."

The complete executive order can read here at the White House website.