APCO-25
P25 P-25 APCO 25 APCO-25 APCO Project 25 Astro-25
Police and public service is migrating to P25 digital mode, making it impossible to listen on traditional analog police scanners.
P25 is a radio system using digital voice via the APCO-25 Common Air Interface (P25 CAI) standard. P25 is a standard developed for public safety trunked radio systems. They follow the open APCO Project 25 standard.
Project 25 uses the IMBE vocoder. IMBE stands for Improved Multi-Band Excitation, and was developed by DVSI Inc. Numerous vendors have produced Project-25 capable subscriber equipment, including Motorola, M/A COM, EF Johnson, Uniden, Racal, and others. There are conventional voice solutions as well as trunking solutions available for this digital voice solution.
Currently, there are two trunking solutions available that use the P25 IMBE vocoder:
- Motorola ASTRO IMBE
- Project 25 Digital Trunking
- P25 Phase one is FDMA
- P25 Phase two is TDMA
Scanner support for FDMA
The following scanners can only decode P25 Phase I, but not Phase II:
- GRE PSR-500, PSR-600
- Radio Shack Pro-96, Pro-2096, Pro-106, Pro-197, Pro-651, Pro-652
- Uniden BC296D, BC796D, BCD396T, BCD996T, BCD996XT,BCD396XT, HomePatrol-1
- Whistler WS1040, WS1065
Scanner Support for TDMA
- GRE PSR-800 (with firmware upgrade, not out of the box)
- Radio Shack Pro-668
- Uniden BCD325P2, BCD436HP, BCD536HP, BCD996P2, HomePatrol-2
- Whistler WS1080, WS1088, WS1095, WS1098, TRX-1, TRX-2
The TDMA support scanners also do FDMA Phase I
