Project 25 Technology Information Group

Monday, June 25, 2018

Project 25 Technology Information Group

Project 25 System of the Month:

Metropolitan Area Regional Radio System (MARRS), Kansas City

Mission Critical Magazine recently published an outstanding profile and history of the Kansas City P25 Regional Radio System.  The article was written by Jack Hart of Tusa Consulting Services, who has been the lead radio consultant for MARRS.

An excerpt from the introduction of the article is below. 

“A Kansas City area Project 25 (P25) network serves as a benchmark for multistate and regional public-safety radio communications.

By Jack Hart, Tusa Consulting Services

In less than eight years, MARRS has evolved from several incompatible, vendor-proprietary trunked systems and a conglomeration of conventional VHF, UHF and 800 MHz local systems into an integrated network that covers more than 4,000 square miles and serves a population of 1.2 million people. The entire system is designed to serve a portable on-hip user.

    MARRS consists of six large simulcast nodes plus multisites, for a total of 48 tower locations. The system supports radio traffic generated by more than 200 public-safety and public-service agencies across six counties — four in Missouri and two in Kansas — including 24 public-safety answering points (PSAPs). On an average day, system use is less than 50 percent, allowing sufficient available radio channel headroom for increased call volume because of a major incident or multiple incidents.”

The complete Mission Critical Magazine article can be accessed with the link below:

The Project 25 Technology Interest Group is pleased to welcome our newest member Compliance Testing LLC.  Compliance Testing is a Full service Test Lab located in Mesa Arizona.  They offer Project 25 CAP testing services along with a wide array of other testing protocols including FCC, IC, CE, EMC, EMI, RF, SAR, and ETSI.  As a full service test lab with over 50 years experience, they can complete the entire FCC, IC, or CE compliance testing process for a client.

Most recently Compliance Testing has been promoting the concept of a single point test lab offering a multi-vendor P25 infrastructure test bed for P25 interoperability testing.  This concept would simplify and streamline P25 interoperability testing by eliminating the need and costs associated with visiting multiple P25 infrastructure vendors labs for testing. 

In addition, Compliance Testing published a recent P25 CAP AP report based on the CAP AP open meeting held at the APCO conference this year.  A link to this report is below. 

For more information on Compliance Testing P25 Services contact:

Chris Lougee

Director, New Business Development

480 748 4449  

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

Brett Gassaway

VP, Business Development



P25 CAP AP Meeting Report from Compliance Testing

The Project 25 technology Interest Group (PTIG) presenbted two panels as part of IWCEs College of Technology in March.  These presentations are now available for review and download.

P25 Foundations IWCE 2016 Part 1

P25 Foundations IWCE 2016 Part 2

P25 User Experience IWCE 2016


The Abstracts for each panel are listed below 

P25 Foundations

Many P25 stakeholders and users today face daunting challenges for clarity of choices and challenging issues of emerging technologies. The material will emphasize the P25 radio and system capabilities deliverable today, resources available for testing, technical guidance, migration planning, and system integration. Gain insight on the next phases of the P25 Standards development, and what those next steps may yield for harmonizing future capabilities with P25 in your LMR systems.

Completed P25 Standards, recently published updates, and future P25 work priorities will be covered. Content includes: Phase 1 FDMA systems, expanding deployment of Phase 2 TDMA systems, and Wireline interfaces including the ISSI, CSSI, and FSI. These interfaces continue to reinforce multiple vendor compatibility in system to system links, console and fixed station product choices as well as in subscriber/mobile/portable equipment.

A specific section on Project 25 CAP testing will be presented including test procedures and specs and their use by DHS.

Ongoing work on new standards for Project 25 System security and encryption will be presented as well as possibilities for the interface for P25 LMR and LTE data systems.

P25 User Experience

This panel and workshop session will derive content from Project 25 user experiences and system case histories. It is structured as a series of presentations from a diverse user group including Federal, State and Local government Systems. Each panel member will conduct a short prepared PPT briefing describing their P25 system, it's scope, capabilities, agencies served, development, interoperability achieved, issues resolved, and lessons learned.

P25 in Planning and Procurement. Including P25 product testing

-- P25 Experiences during Implementation and Deployments.

-- Interoperability with neighbors and overlapping jurisdictions.

-- Experiences with Multiple Vendors Systems, Equipment, Interfaces.

-- Lessons learned and best practices established for P25 system design, user training, and governance structure

Other Technology Resources beyond Manufacturers and Equipment Suppliers: Consultants, Integrators, Third Parties.

There will be open Q&A time allocated for panel members on each separate segment.

MissionCritical Communications Publishes P25 E-Book


MissionCritical Communications magazine has published a comprehensive update and guide to Project 25 Technology and its applications titled “P25: Advances in Interoperability and the Technology’s Future” The 139 page document includes sections on: P25 History and a Standards Update, Interoperability and Technology, FirstNet and P25, User Deployments, and P25 Around the World.


A number of the reports in the E-book were contributed by PTIG and PTIG members including our Whitepaper “Is P25 Public Safety Grade?” In addition, PTIG members have made the E-book possible by their support as Sponsors. PTIG sponsors include: Harris, Cobham, JVCKenwood, Zetron and Avtec.


You can register to download the complete P25 E-book using the link below:


P25 E-Book Forward: Strides in Interoperability

By Sandra Wendelken


Following Project 25 (P25)’s 25-year anniversary in 2014,

the standard has continued on its journey to enhance


Progress continues with the wireline interfaces, including

the Console Subsystem Interface (CSSI) and the Inter Subsystem

Interface (ISSI). These standards are important to the technology’s

continued evolution. Several push-to-talk (PTT) vendors are using the CSSI

to connect P25 networks with commercial Long Term Evolution (LTE)

technology and extend PTT services to users with smartphones on

commercial networks. This development will be one to watch as the First

Responder Network Authority (FirstNet) gets rolling.


In addition, a study item on a standard for LMR, including P25, and LTE

interworking was submitted to the Third Generation Partnership Project

(3GPP) for consideration in an upcoming release of LTE. The federal Public

Safety Communications Research (PSCR) program is also working to

integrate P25 and LTE in the future.


A new advisory panel (AP) was established in late 2015 to help get the

P25 Compliance Assessment Program (CAP) moving forward again.

Funding from the Department of Homeland Security (DHS) will help ensure

the program continues down the right path. The AP is comprised of P25

users who have a strong desire to maintain the program and the benefits it

has for users.


P25 users must do their part to remain educated about the

latest developments in the technology and to ensure the equipment they buy

adheres to all the standards. Ignorance means a compromised system. If

you don’t have time to do the proper research it’s advised to hire a credible

consultant. Users have made a good first step by downloading this e-book,

which provides all the latest information on the standard, interoperability,

integration with FirstNet and helpful user deployment details. The e-book

offers a wealth of information to ensure P25 procurements run smoothly and

cost effectively.

This Updated FAQ document has 14 new questions and significant changes to P25 testing questions from the recent Compliance Assessment Program (CAP) open meeting. In addition, the document has been reconfigured to categorize the questions by topic making the document easier to use for quick reference.

The first category is now an individual section for a P25 Standards Overview, including a question on how the P25 Standards are created. The second category deals with P25 Compliance testing and has been updated to reflect the latest DHS OIC Web links and document availability. The other categories include information that describes the relationship of P25 to other radio technologies, Interoperability possible through the numerous Project 25 interfaces with real world examples of existing systems, and the Project 25 Security Services available.   

PTIG offers the FAQ tool to Public Safety and government users who need to deliver a simplified, top level, answer to typical P25 questions received from non-technologist personnel including Police Officers, Fire fighters, administrators, procurement contracting officers. Most of the questions have been received by PTIG at various P25 conference panels and trade shows that the group participates in.

The Project 25 Suite of Standards will continue to evolve to meet the needs of users and to incorporate changing technology and regulatory mandates.  Similarly, this document will also evolve over time.  Subsequent versions will add new questions and clarify answers reflecting the latest updates to the P25 Standard.

Copies of the new Project 25 Frequently Asked Questions v1.2 document can be found and downloaded from the link below

P25 FAQs September 2016 v1.3





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