Project 25 Technology Information Group

Tuesday, December 12, 2017

Project 25 Technology Information Group


The Project 25 Technology Interest Group (PTIG) has developed a new whitepaper on the benefits of P25 technologies for use in Fire ground operations.  Many improvements to the P25 Standards, the P25 vocoder and the P25 products available make it a good time to revisit P25 as a technology for Fireground use.  A summary of the key points is below.   The complete whitepaper can be found using the following link.

A good time to revisit P25 for use on the Fire ground


Summary Benefits of using P25 mission critical radio equipment for the Fire ground include:

  • Improved P25 performance in background noise. P25 equipment can now achieve 10 to as much as 25 dB improvements in background noise reduction.
  • Tone Signaling – DTMF, Knox and single tone is now supported.
  • Paging – P25 Paging receivers are now available.
  • Improved Coverage – P25 Phase 1 technology is about +7dB better than 25 KHz Analog.
  • Enhanced Signaling – Talking Party ID, Group Calls, Unit-to-Unit Calls, All Calls, Emergency Alerts, Emergency Calls, Call Alerts, Radio Check, Radio Unit Monitoring and others.
  • Location Services – Integrated GPS receivers provide location information.








Project 25 Technology Interest Group

P25 System of the Month – May 2016

Iowa Multi-County Radio System


Six Iowa Counties connect their separate P25 systems together for a unique blend of local control and regional interoperability

Six large counties in Iowa – Polk, Marshall, Grundy, Linn, Johnson and Blackhawk – are connecting their separate Harris 700/800 MHz P25 simulcast trunking systems together in an effort to reap the benefits of region wide coverage and interoperability while still retaining local control of important system design criteria like in-building coverage, capacity and local redundancy.  


Johnson County, Iowa (county seat of Iowa City and home to the University of Iowa) released an RFP in 2008 to replace their outdated analog 800 MHz trunking system with a P25 system.  Harris won that bid and installed the 800 MHz P25 trunked simulcast system in 2010.  Johnson County’s immediate neighbor to the north, Linn County, released an RFP in late 2010, also to replace their analog trunking system with P25.  Harris and their local partner RACOM provisioned the Linn County system so it was directly connected to the Johnson County system.  While each County has their own P25 central network core, each shares a redundant central database which makes them aware of the surrounding peers and their assets.  Each core is able to efficiently route talk groups and other traffic between the cores that have demand for it, while not sending information to the cores that have no need for it.  Since each core is fully aware of its peers, users are able to seamlessly and without end user intervention roam from system to system without concern for which county’s towers were being accessed.

According to Charlie McClintock, Communications Director with the City of Cedar Rapids in Linn County, IA, “We like being able to have seamless interoperability with our Johnson County partners and an extended coverage area into multiple counties without having to sacrifice important elements of our own system like having our own P25 network switching center resources and in-building portable coverage custom designed for us.  The Harris & RACOM solution allowed us to have the best of both.”

Growth to Other Counties

The positive experience in Linn and Johnson Counties got those Sheriffs to begin to collaborate with their neighbor to the north - Black Hawk County, IA.  Black Hawk County released an RFP to replace another analog trunking system with P25 in early 2015 and will be the third county to become a part of the expanding network late this year.

Three other Iowa counties: Grundy, Marshall and Polk, all recently upgraded their aging 800 MHz Harris EDACS-based land mobile radio systems to P25 through their partnership with RACOM.  The public private partnership has RACOM owning the P25 switch resources and most of the P25 tower site infrastructure in exchange for extended service and maintenance from the public safety partners.  These systems are also being connected to the network in a manner that creates wide coverage areas, seamless interoperability and intuitive roaming among all six counties.

Local Control

Many states, including Iowa, have built or are building state-owned and controlled P25 systems that allow local usage.  These six counties preferred this model because they can reap the benefits of wide area coverage and seamless interoperability that state systems offer without having to sacrifice the important local control elements of local redundancy, in-building coverage and seamless integration with other important systems like fire paging and 911 telephone.

Planning and Coordination

While the original Johnson and Linn County systems were designed to be a single system from the beginning, ensuring the other four county systems and other systems to be added in the future have similar system IDs, IP address schemes and non-conflicting end-user ID’s has taken careful planning and great coordination.  In collaboration with each of the counties key personnel, a single talk group and unit id plan was agreed to that allocated 500 talk groups (including several unallocated interoperability talk groups) and up to 10,000 unit id’s for each agency in a county (up to 100,000 unit ids total in each county).  

Collaboration – Open Standards

Collectively, the P25 systems in these six counties have nearly 100 separate public safety/public service agencies and 6,000 radios.  Departments not only have different requirements for their radios, but also vastly different budget capacities and timelines.  Open and competitive procurement of P25 end user radios is very important.  The Harris P25 infrastructure in these six counties is currently supporting P25 end user radios from Harris, Tait, EFJohnson, Motorola and Kenwood.

To see how your P25 System can be nominated as a P25 System of the Month


Stephen Nichols

Director, Project 25 Technology Interest Group

This email address is being protected from spambots. You need JavaScript enabled to view it.

Project 25 Technology Interest Group Welcomes a New Member, LocusUSA


The Project 25 Technology Interest Group is pleased to welcome a new member to the organization.  LocusUSA has developed a radio analyzer that can analyze Project 25 subscriber radios over the air.  LocusUSA is an engineering and software development company located on the Space Coast of Florida since 2001.  Their focus is research in the area of RF capture for location and analysis.  The ability to capture and analyze the characteristics of the radio waveform led to the development of its DiagnostX system that can ascertain the alignment and other key metrics of a radio, Over-The-Air (OTA) in real time.  LocusUSA supports government customers across the US and Canada on the local, state and federal levels with this first-of-its-kind, proactive tool, ensuring the optimal performance of their radio systems.

For more information on Locus USA and their products contact:

Jim Zaleta, This email address is being protected from spambots. You need JavaScript enabled to view it., 321-727-3077, X110

WEB address link

Project 25 Technology Interest Group Releases a New Whitepaper:

Technology Benefits of P25

Over the years, the most often selected article on the Project 25 website is the one describing Technology Benefits of P25.  This article has been recently updated to include the new wireline interfaces (ISSI, CSSI, FSI) and new operational capabilities recently added to the P25 suite of standards.

The Whitepaper covers the background and history of the P25 Standard, original goals and objectives, a summary overview of the standards and how they translate into benefits for the Public Safety community.  A copy of the complete whitepaper can be downloaded using the following link

Technology Benefits of P25

P25 Goals and Objectives

From the beginning, P25 has targeted four primary objectives:

  • Allow effective, efficient, and reliable intra-agency and inter-agency communications
    … so organizations can easily implement interoperable and seamless joint communication in both routine and emergency circumstances.
  • Ensure competition in system life cycle procurements
    … so agencies can choose from multiple vendors and products, ultimately saving money and gaining the freedom to select from the widest range of equipment and features.
  • Provide user-friendly equipment
    … so users can take full advantage of their radios’ lifesaving capabilities on the job – even under adverse conditions – with minimal training.
  • Improve radio spectrum efficiency
    … so networks will have enough capacity to handle calls and allow room for growth, even in areas where the spectrum is crowded and it’s difficult for agencies to obtain licenses for additional radio frequencies.

P25 Benefits Delivered

  • Ability to Meet In the Air
  • Interoperability Among Agencies
  • Interoperability Among Vendors
  • Spectral Efficiency
  • Integrated Voice and Data Services


  • Scalable Secure Systems using Conventional and Trunking in all LMR bands.
  • Competition from 34 suppliers of P25 Products and Services


The Project 25 Technology Interest Group (PTIG) has published the complete P25 Steering Committee By-laws as an information resource for the P25 User Community.


Project 25 is a unique user-driven process created to establish current and emerging wireless communications standards that meet the requirements of the public safety community. In this standards development process, Project 25 is directly involved with users and manufacturers. It also involved the development of a partnership with the TIA. Using the TIA Engineering Manual, TIA may develop a suite of technical standards, telecommunications system bulletins and technical white papers that enable the development, manufacture and operation of interoperable Project 25 communications systems and system components that satisfy the Project 25 adopted requirements.


Subsequent to signing the MOU, in 1993 APCO officially changed its name to the Association of Public-Safety Communications Officials-International, Inc. In 2007, NASTD officially changed its name to the National Association of State Technology Directors.
The formal relationship with TIA was established through the execution of a MOU that outlines the responsibilities and obligations of both parties and the framework that TIA and Project 25 agreed to work within.


A key element of the MOU is the clear understanding that the Project 25 Steering Committee may choose to select any standards proposal, telecommunications system bulletin, or white paper as a P25 Standard, but a TIA/Project 25 standard can only be created in accordance with the TIA-approved Engineering Manual, policies, and rules and regulations that coincide with the requirements of the American National Standards Institute (ANSI) process for Standards Development Organizations (SDO).


The Project 25 Standards Process is based on users determining the functionality and critical interfaces that require standardization to ensure interoperability among Project 25 system components produced by any manufacturer. While it is a user driven process, it is done in cooperation with industry to ensure both the expectations and deliverables can be achieved. These functionalities and interface requirements are documented in the Project 25 Statement of Requirements (P25 SOR). The P25 SOR is in turn approved and maintained by the P25 Steering Committee. Formal standard documents are developed, balloted, published, and maintained by the TR-8 Mobile and Personal Private Radio Standards Committee of the Telecommunications Industry Association (TIA).

The P25 Steering Committee By-law document can be accessed using the link below:


Project 25 Steering Committee By-laws







Web Boy Design Website Development by Web Boy Design, Inc