DMR Tier II refers to a classification within the Digital Mobile Radio (DMR) standard, which is used for professional mobile radio communications. This tier is designed for users who require basic voice communication and limited data services. It supports a single-slot operation, allowing for two simultaneous voice calls on a single frequency. In contrast to DMR Tier I, which is intended for unlicensed use, DMR Tier II operates on licensed frequencies, providing more reliable communication. It is commonly used by businesses, public safety organizations, and other entities that need secure and efficient radio communication systems.