N.C. Gen. Stat. § 20-196
The Secretary of Public Safety, through the State Highway Patrol is hereby authorized and directed to set up and maintain a statewide radio system, with adequate broadcasting stations so situate as to make the service available to all parts of the State for the purpose of maintaining radio contact with the members of the State Highway Patrol and other officers of the State, to the end that the traffic laws upon the highways may be more adequately enforced and that the criminal use of the highways may be prevented. The Secretary of Public Safety, through the State Highway Patrol, is hereby authorized to establish a plan of operation in accordance with Federal Communication Commission rules so that all certified law-enforcement officers within the State may use the law enforcement emergency frequency of 155.475MHz.
The Secretary of Public Safety is likewise authorized and empowered to arrange with the various telephone companies of the State for the use of their lines for emergency calls by the members of the State Highway Patrol, if it shall be found practicable to arrange apparatus for temporary contact with said telephone circuits along the highways of the State.
In order to make this service more generally useful, the various boards of county commissioners and the governing boards of the various cities and towns are hereby authorized and empowered to provide radio receiving sets in the offices and vehicles of their various officers, and such expenditures are declared to be a legal expenditure of any funds that may be available for police protection.
N.C. Gen. Stat. § 20-196