A communications network to transport the digital information from phasor measurement units (PMUs) to where the data will be used. Typically implemented using a private wide-area network (WAN), this network can be any digital transport system that offers acceptable security and availability. Functional requirements have been developed as part of the North American SynchroPhasor Initiative (NASPI) to provide for flexible, fast, vendor-agnostic, and secure communication of phasor measurements.