Project 25 Documents & Standards Reference

Revised SEP 3, 2010

Introduction

The formal P25 (Project 25) standards development process is conducted by the TR8 (Mobile and Personal Private Radio Standards) Committee of TIA (Telecommunications Industry Association)’s Standards and Technology Department. TIA is accredited by ANSI (American National Standards Institute) to develop voluntary industry standards for a wide variety of telecommunications products.

Project 25 (Project 25 was established by joint efforts of the Association of Public Safety Communications Officials International (APCO), the National Association of State Telecommunications Directors (NASTD), selected Federal Agencies and the National Communications System (NCS). It was established to address the need for common digital public safety radio communications standards for First Responders and Homeland Security/Emergency Response professionals.) is unique in that it is a user-driven process to develop a family of public safety communications standards for which the requirements have been defined by state, local and federal government users.

User Representative Steering Committee

P25 is directed by a steering committee composed of user representatives from federal agencies, state governments, and local governments. All activities of the P25 process must be approved by the steering committee and TIA in accordance with the MoU (Memorandum of Understanding) consummated in 1993. Members of the public safety community attend regular meetings of APIC (Association of Public-Safety Communications Officials (APCO) Project 25 Interface Committee) which was established under the MoU to facilitate TIA’s development standards that can be adopted as part of the P25 standards suite.

Digital Modulation and Spectrum Efficiency Two-Phase Plan

P25 represents the public safety community’s overall strategy to develop a digital modulation solution and achieve FCC (Federal Communications Commission) spectrum efficiency mandates calling for eventual migration to narrowband channel spacing in the VHF (very high frequency) and UHF (ultra high frequency) bands, which call for an eventual four-to-one reduction in spacing from 25 KHz (kilohertz) to 6.25 kHz equivalent per voice channel.

P25 addresses the FCC’s mandate with a two-phase plan.

Phase 1 defines the necessary technologies to provide for channel reduction from 25 kHz to 12.5 kHz. Phase 1 refers to P25 requirements and standards for a digital CAI (Common Air Interface) based on FDMA (Frequency Division Multiple Access) using a 12.5 kHz channel.
Phase 2 defines an additional 50 percent reduction in channel size to 6.25 kHz or equivalency. Phase 2 refers to P25 requirements and standards for a digital CAI TDMA (Two-Slot Time Division Multiple Access) using a 6.25 kHz equivalent channel, two slots in a 12.5 kHz channel.

Requirements Driven

P25 standards are driven by a public safety user-defined P25 SoR (Project 25 Statement of requirements) and an over-all approach to the development of the standards via a system description and organization document. The organization of the standards divides the suite into documents relating to P25 system interfaces, services, and equipment. Associated with each interface, service, and equipment section is a set of documents that does either of the following:

Describe and specify the standards appropriate to the section.
Describe tests to demonstrate compliance of the offered interface, service, and equipment to the standards.