Project 25

Go to the TR-8, Mobile and Personal Private Radio Standards Web page.

Public Safety Radio Communications: The Wireless Industry to the Rescue

TIA acts as a catalyst for the wireless industry to develop and maintain public safety standards for digital equipment and systems that will assist the life-saving and damage-control activities of first responders at the scene of an emergency or disaster situation. This activity, known as Project 25 (P25), is supported by industry, government agencies and public safety communications officials alike, including the Department of Homeland Security's National Communications System (NCS), the Department of Defense, and the National Telecommunications and Information Administration (NTIA).

P25 Overview

Work Activities of TIA TR-8 Engineering Committee, Mobile and Personal Private Radio Standards
The engineering committee and its subcommittees develop and maintain standards for private radio communications systems and equipment for both voice and data applications. TR-8 addresses all technical matters for systems and services, including definitions, interoperability, compatibility and compliance requirements.

Project 25
Recognizing the need for common standards for first responders and homeland security/emergency response professionals, representatives from 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) established Project 25, a steering committee for selecting voluntary common system standards for digital public safety radio communications. TIA TR-8 facilitates such work through its role as an ANSI-accredited Standards Development Organization (SDO) and has developed in TR-8 the 102 series of technical documents.

P25-compliant systems are being increasingly adopted and deployed. Radios can communicate in analog mode with legacy radios and in either digital or analog mode with other P25 radios. Additionally, the deployment of P25-compliant systems will allow a high degree of equipment interoperability, compatibility and economy of scale. Specifically, P25 systems can be maintained and upgraded cost effectively over the system's life cycle, thus meeting user requirements, achieving interoperability and security, promoting committed manufacturers to provide compliant products, fostering competition and achieving cost-effective emergency/safety communications solutions. In light of recent worldwide terrorist activities, interoperability among first responders is a key initiative of many countries.

The P25 suite of standards involves digital Land Mobile Radio (LMR) services for local, state and national (federal) public safety organizations and agencies. P25 is applicable to LMR equipment authorized or licensed, in the United States, under National Telecommunications and Information Administration (NTIA) or Federal Communications Commission (FCC) rules and regulations. However, use of such equipment is not limited to public safety, and P25 equipment has also been selected and deployed in other private system applications, for example, to serve the needs for a high-quality, secure digital radio system for a railroad system, including rolling stock, personnel and transportation vehicles.

P25-compliant technology is being deployed in several phases, based on TIA engineering committee work and the P25 standards TIA ultimately publishes. Vendors are currently shipping Phase I P25-compliant systems. These systems involve standardized service and facility specifications, ensuring that any manufacturer's compliant subscriber radio has access to the services described in such specifications. Abilities include backward compatibility and interoperability with other systems across system boundaries, regardless of system infrastructure. In addition, the P25 suite of standards provides an open interface to the radio frequency (RF) subsystem to facilitate interlinking of different vendors' systems.

P25 Phase II implementation involves time and frequency modulation schemes (e.g., TDMA and FDMA), with the goal of improved spectrum utilization. Significant attention is also paid to interoperability with legacy equipment, interfacing between repeaters and other subsystems, roaming capacity and spectral efficiency/channel reuse. In addition, Phase II work involves console interfacing between repeaters and other subsystems, and man-machine interfaces for console operators, which would facilitate centralized training, equipment transitions and personnel movement.

Recognizing the need for high-speed data for public-safety use, as expressed in the Public Safety Wireless Advisory Committee (PSWAC) Final Report, the P25 standard committee established the P25/34 committee to address Phase III implementation. Phase III activities address the operation and functionality of a new aeronautical and terrestrial wireless digital wideband/broadband public safety radio standard, which could be used to transmit and receive voice, video and high-speed data in a ubiquitous, wide-area, multiple-agency network. Due to common needs, the European Telecommunications Standards Institute (ETSI) and TIA have agreed to work collaboratively for the production of next-generation mobile broadband specifications for public safety users. Today, this international collaboration is known as Project MESA (Mobility for Emergency and Safety Applications). Visit TIA's Project MESA Web page for more information on advanced communications needs. Current P25 systems and future Project MESA technology will share many compatability requirements and functionalities.

P25 Links and Information:

For more information on TIA activities like P25, please visit the related Web sites or contact John Derr at +1.703.907.7791.

Go to the TR-8, Mobile and Personal Private Radio Standards Webpage.

Search Standards

View Advanced Search

Search in:
Publication Number
Primary Subject
Secondary Subject


Standards & Technology Annual Report (STAR)

A summary of the latest actions taken by the respective TIA engineering committees.

Learn More

TIA Cloud Computing White Paper

TIA Cloud Computing White Paper

This white paper analyzes how TIA's engineering committees could address existing cloud computing standardization gaps.

Learn More

TIA Engineering Manual

This manual describes the manner in which the standards activities of TIA are organized and the manner in which its activities are conducted.

Learn More