In a Department of Defense Directive and Instruction Sheet regarding Land Mobile Radio (LMR) Interoperability and Standardization, the DoD states all LMR equipment procured after July 28 will conform to Project 25 (P25) standards.
DoD equipment should be capable of operating between 138 – 869 MHz using either P25 Phase 1 or 2 modulation and signaling or narrowband (12.5-kilohertz deviation) with associated Continuous Tone-Coded Squelch System/Digital Coded Squelch (CTCSS/DCS) signaling to facilitate direct interoperation with non-DoD P25 and FM LMR systems.
Trunking networks will comply with the P25 trunking specification, testing and compliance assessment documents. LMR wide-area networks will comply with the P25 Inter RF Subsystems Interface (ISSI) specification, testing and compliance assessment documents, the instruction sheet said.
Mission Critical Magazine has published an article on the DoD requirement here.