Palomar Amateur Radio Club STEM Experimentation Lab

Project 25 is a digital radio standard meant for two-way public safety communications. Its aim is to provide a standard that can be adopted by by manufacturers to foster interoperability between public safety organizations.

P25 primarily operates in the VHF (136–174 MHz) and UHF (380–512 MHz) bands with control channels in 764–776 MHz uplink and 794–806 MHz downlink, and 800 MHz (806–869 MHz). The 700MHz band is assigned to public safety use in the USA.

Key Features:

• Interoperability of Public Service Agencies: The standardization has really enabled inter-agency coordination and cooperation.
• Secure Voice and Data:The provision of encryption allows for secure communications, especially important for law enforcement and privacy.
• Efficiency:P25 phase one uses C4FM and a 12.5kHz channel width. Phase 2 will use CQPSK modulation and TDMA over a 6.25kHz channel width. Phase 2 is being rolled out currently.

References:
• RFPage  🔗 What is Project 25 (P25)?
• Association of Public-Safety Communications Officials (APCO) International
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