Project 25 (P25 or APCO-25) is a set of standards for modern mobile radio communications that are intended for use by North American public safety organisations. P25 radios are a direct replacement for analog UHF (typically FM) radios, but add the ability to transfer both data and voice, allowing for more natural encryption and text messaging implementations. P25 radios are commonly deployed using vehicle-mounted radios combined with portable walkie-talkie use by dispatch organizations such as police, fire, ambulance, and emergency rescue service. Beginning around 2012, the new Phase 2 modulation protocol made products available, and the older protocol known as P25 became P25 Phase 1. P25 Phase 2 goods use the more sophisticated AMBE2 + vocoder, which allows audio to travel through a more compressed bitstream and offers two TDMA voice channels within the same RF bandwidth (12.5 kHz), while Phase 1 can provide only one voice channel. P25 Phase 2 infrastructure can provide a "dynamic transcoder" function which translates as needed between Phase 1 and Phase 2. In addition, phase 2 radios are, by definition, backward compatible with Phase 1 modulation and analog FM modulation.