Copyright© 2009 Tower Communication & Automation, Inc. “Reaching Beyond The Competition.” Project 25 What is it? Project 25 (P25) is a set of standards produced through the joint efforts of the Association of Public Safety Communications Officials International (APCO), the National Association of State Technology Directors (NASTD), selected Federal Agencies and the National Communications System (NCS), and standardized under the Telecommunications Industry Association (TIA). Benefits of P25 Interoperability Radio equipment that is compatible with P25 standards will allow users from different agencies or areas to communicate directly with each other. Backwards Compatibility A basic requirement for Phase 1 P25 digital radio equipment is backward compatibility with standard analog FM radios. Enhanced Functionality P25 radio systems use 2400 bits per second for signaling capabilities. This allows a vast array of additional functions and features to be standard in any P25 radio system. The signaling capabilities include selective calling (Source and Destination ID), talk groups (TGID), network (repeater) access codes (NAC) and emergency flags all as standard P25 digital features. Encryption Capability The P25 standard includes a requirement for protecting digital communications (voice and data) with encryption capability. The encryption used in P25 is optional, allowing the user to select either clear (un-encrypted) or secure (encrypted) digital communication methods. The encryption keys also have the option of being re-keyed by digital data over the RF links. This is referred to as Over The Air Re-keying (OTAR). Improved Audio Quality With more than one quarter of the channel capacity used for error correction, P25 digital signals have greatly improved voice quality over standard analog signals, especially at low or noisy RF carrier levels. **WyoLink is a P25 VHF Trunking System**