The standards employ state-of-the-art digital technologies rather than the older analog technology of current systems. Apparent user benefits include interoperability between agencies and between different levels of government and competitive procurement. From the user's perspective, standards ensure interoperability, provide backward compatibility to current systems and forward migration to future systems, control system costs, increase spectrum efficiency, and simplify communication system decision processes. APCO Project 25 has the active support of the International Association of Chiefs of Police. Procedures associated with Project 25 are described, particularly with respect to its data rate and spectrum efficiency.