Project 25 Technology Information Group

Wednesday, April 21, 2021

Project 25 Technology Information Group

Many Public Safety and government agencies are realizing significant Cost Savings through P25 Sharing. The Project 25 Technology Interest Group (PTIG) is pleased to share a recent example from the "The Submarine Capitol of the World", Groton Connecticut Police Department.  

" Some of the advantages for the town include greatly enhancing police radio coverage and communications interoperability with neighboring departments to include Stonington, Groton Long Point, Environmental Conservation Police and the State Police. Communications interoperability is an important aspect of modern day policing and can greatly assist on a daily basis, during large scale events, joint operations and ultimately with officer safety. There are additional benefits to joining the state system to include the fact that the town will now maintain less infrastructure, utilize resources from the State of Connecticut and realize savings due to economies of scale by working with other communities and agencies who utilize this system."

"Comparable systems can cost in excess of 3.5 million dollars and the Town of Groton was able to join the state system at a fraction of the cost".


View the full Press Release with Contact information using the link below.


Groton CT Radio System Going Live

The New Primer offering a comprehensive overview of the P25 Inter-RF Subsystem Interface (ISSI) and Console Subsystem Interface (CSSI) is now available and can be downloaded off the PTIG as well as DHS websites.

This document’s purpose is to introduce the Inter-RF Subsystem Interface (ISSI) and Console Subsystem Interface (CSSI) technologies and highlight potential benefits and uses, discuss the existing Project 25 (P25) LMR standards that govern the technologies, briefly introduce some of the challenges associated with the implementation of the standards, and discuss how best to address these challenges in the future.

The document was developed by SAFECOM, The Federal Partnership for Interoperable Communications (FPIC) and the National Council of Statewide Interoperability Coordinators (NCSWIC)

The document provides a high-level overview of a broad range of introductory topic areas relevant to ISSI and CSSI, including:

  • •Overview of ISSI/CSSI technology,
  • •Benefits of ISSI/CSSI,
  • •How Project 25 standards address ISSI/CSSI,
  • •ISSI/CSSI planning and implementation challenges,
  • •Resources for effective ISSI/CSSI implementation, and
  • •Current FPIC ISSI/CSSI Focus Group activities

The primer can be downloaded using the link below


or from the DHS website at:



PTIG at IWCE 2019

Visit our Booth # 2761

  • · See the latest P25 Products and Information
  • · Meet P25 Consultants, System Managers and Engineers
  • · Enter to win a Bose headset in our Raffle sponsored by CTA Consultants
  • · See the New P25 Testing Table with a display of the latest P25 Testing Products and Services in Development

Attend PTIG Panels

  • · Learn about the Interworking of P25 LMR and LTE technology
  • · Learn about New P25 Interoperability possible through the Inter Sub System Interface (ISSI) and Console Sub System Interface (CSSI)
  • · See how P25 Sharing can reap significant Cost Savings for your agency
  • · Learn about the New P25 Link Layer Encryption and how it can protect the identity of your P25 radio users.
  • · Learn what is New in the P25 Standards and How it will affect your existing system.
  • · Learn about the Latest New P25 Products and Services from: Intertalk, Compliance Testing, PCTEL, Harris, ICOM, Catalyst, Telex, JVC Kenwood, Unications, Codan, Futurecom, Locus, Valid8, Avtec, Etherstack


P25 for the Future: New Products, Applications, Interoperability and Security

3 Hour Panel Session: Tuesday, March 5 * 8:30 am -11:30 am * Room N256


Project 25 with LTE: Mission Critical PTT Interworking Standards in Development

1:15 Hr. panel session: Thursday, March 7 * 2:15 pm – 3:30 pm * Room N261

Other P25 Sessions of Interest

Tuesday March 5th

12:30PM-2:00 PM CAP AP Open Meeting  Room N240

Sridhar Kowdley

Wednesday March 6th

2:45 PM – 4:00 PM  Interoperability: ISSI/CSSI/DFSI  Room N261

Jim Downes

10:15 am - 11:30 am Protections, Capabilities, and Real-World Deployments of Encryption Protocols   Room: N258

Jim Downes

Thursday March 7th

3:45 PM-5:00 PM CAP Testing of ISSI/CSSI  Room N261

Sridhar Kowdley


For more Information contact Stephen Nichols, Director PTIG 301 466 5206

The Project 25 Technology Interest Group has published the first ISSI/CSSI Non CAP Interoperability Test Reports. The testing was done between a Motorola RFSS and an Avtec Scout Console.

The information contained in the report has been provided by the suppliers of the products with permission to make the information publicly available. The Project 25 Technology Interest Group (PTIG) is making this information available as a public service.

If you have questions regarding the testing please contact the signatories to the test report using their email found on the Gerneral Information tab of the report.


A copy of the report can be downloaded using the link below:


190220 MSI-Avtec Non CAP ISSI/CSSI Interoperability Test


New PTIG Whitepaper: What is P25 Compliance?

This paper is intended to explain different levels of compliance statements that may be used by customers or consultants when specifying an equipment purchase or used by manufacturers promoting equipment capabilities.

In general, “Project 25 (P25) compliance” is typically interpreted as: “adherence to the P25 standard”.

The P25 Standard is composed of over 80 documents that cover multiple interfaces, multiple services and multiple features associated with each interface or service. Therefore, questions or statements about compliance to the “P25 standard” are really too vague to provide the understanding typically desired by those asking the questions or making the statements. Questions or statements about any level of compliance are more effectively expressed in the context of a specific interface, a specific service or a specific feature that is covered by a published P25 standard document or in the context of a specific standard document. For example, the statement: “My equipment is P25 compliant” is difficult to correctly interpret because it does not identify any P25 standard interface or service or document or set of features. A better statement would be along the lines of: “My radio is compliant to the P25 FDMA Air Interface, Trunking service, Group Voice Call feature.”

Four levels of assessing compliance are commonly used and are discussed in the Whitepaper. The P25 user and manufacturer community should use the four levels of compliance when referring to the requirements or capabilities of P25 products, features and services.


A copy of the Whitepaper can be downloaded using the link below:


PTIG Whitepaper: What is P25 Compliance?





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