Analog or analogue is a transmission method of conveying voice and or data information using a continuous signal which varies in amplitude, phase, or some other property in proportion to that of a variable. It could be the transfer of an analog source signal, using an analog modulation method such as frequency modulation (FM) or amplitude modulation (AM), or no modulation at all.
Digital Mobile Radio (DMR) is an international digital radio standard developed by the European Telecommunications Standards Institute (ETSI), and first ratified in 2005. More than a decade ago, vendors and users of radio systems recognized that the existing analog trunking standards required updates with modern techniques to provide: Improved voice quality Improved functionality such as Location information) Improved security (i.e. Authentication and Encryption) Improved channel efficiency (2 slot TDMA)
P25, or Project 25, is a suite of standards developed to provide digital voice and data communication systems suited to public safety and first responders. Project 25 was initiated by the Association of Public Safety Communications Officials, or APCO. APCO International is the world’s oldest and largest organization of public safety communications professionals.