Project 25 Technology Information Group

Wednesday, January 26, 2022

Project 25 Technology Information Group

Project 25 Technology Interest Group (PTIG) Welcomes Sonia Kendall to the Board of Directors.

The Project 25 Technology Interest Group (PTIG) is pleased to welcome Sonia Kendall, US Coast Guard, to the PTIG Board of Directors. “Sonia’s experience with P25 Interoperable Communications and her longstanding participation in the TIA TR-8 P25 Standards process makes her an ideal addition to our Board. Many of our P25 User agencies require reliable interoperable communications with the US Coast Guard and Sonia can help establish and maintain these relationships” said Stephen Nichols, PTIG Director. “She can well represent the specific user needs from the US Coast Guard perspective”.

Ms. Kendall is currently assigned to the office of Office of Enterprise Architecture and Technology Innovation (CG-67) as the Coast Guards communications interoperability coordinator for Public Safety communications. In this position she coordinates interoperability efforts of the Department of Homeland Security, Federal, State, and local port partners. Additionally, she represents the Coast Guard in national telecom standards, regulatory and advisory organizations and she liaisons with Coast Guard program managers affected by these standards and regulations. She also oversees long range communications and Coast Guard record messaging from a programmatic and policy perspective.

Ms. Kendall holds an MBA Degree from Columbia Southern University, a Bachelor of Science Degree in Information Systems Management from the University of Maryland University College, and a General Associate’s Degree from Phoenix University.

Prior to this assignment, Ms. Kendall was active duty Coast Guard and served as the Satellite Communications Asset Manager. Her 25-year Navy/Coast Guard active duty career (Enlisted – Warrant- LT) was solely focused in Control, Communications, Computers and Information Technology related work.

The Project 25 Technology Interest Group (PTIG) has published the latest ISSI/CSSI Non CAP Interoperability Test Report. The testing was done between a Telex C-Soft P25 Console and a Tait P25 RFSS.

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:


TELEX-TAIT Non-CAP ISSI-CSSI Interoperability Test

PTIG publishes a new Case Study on the P25 VIPER System in North Carolina


At the recent TIA TR-8 P25 Standards Meetings in Charlotte North Carolina, an overview of the North Carolina VIPER System was presented by Greg Hauser.  Greg is the Communications Branch Manager and Statewide Interoperability Coordinator (SWIC) for North Carolina Emergency Management.  The Case Study includes "Wins" and Gaps" for the 122,000 users on the Statewide P25 Network.


The Case study can be viewed using the link below:

P25 Viper System, North Carolina

Project 25 Technology Interest Group

P25 System of the Month

Regional Wireless Cooperative

Phoenix AZ


Ron Parks, Radio Communications Analyst, Chandler Police Department

Across the Phoenix Metropolitan Region, Police, Fire, EMS and other municipal services utilize a well-maintained and highly reliable state of the art P25 trunked radio system. Formed in 2008, the Phoenix area Regional Wireless Cooperative (RWC) supports 19 member agencies, representing the majority of cities, towns, and fire districts across the “Valley of the Sun.” The cooperative provides governance, quality infrastructure, economy of scale, and freely shares interoperability resources with non-members.


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The RWC is a cooperative body formed under Intergovernmental Agreements (IGA) with direction provided by a Board of Directors made up of one representative from each member and overseen by an Executive Director and staff. While the City of Phoenix serves as the Administrative Manager for administration, financial management, and staffing, each member from the smallest to the largest has an equal vote in the operations and governing of the cooperative. Membership categories include full members, associate members (such as contracted ambulance services,) conditional participants (not yet full members), and interoperability participants. Funding is provided through per-subscriber membership fees that are based on the number of subscribers on the system, assessed on an annual basis.


The RWC has created multiple interoperability talkgroups in subscriber zones that are freely shared with both members and non-members for interoperable purposes when working with RWC member agencies. These wide-area roaming talkgroups are part of a standards-based regional plan that includes immediate tactical operations as well as groups reserved for planned in advance operations and events. These resources are shared with local, regional, state, federal, and tribal entities throughout central Arizona and are in use on a daily basis. Resources include both unencrypted and encrypted talkgroups with interoperable encryption enabled by sharing of a single common AES-256 encryption key. All encryption is managed via Over The Air Rekeying (OTAR) either from a central server in Phoenix (primarily for members) with the key material also provided to any area system with their own key management server and OTAR capabilities. Large-scale events such as the NFL Pro Bowl and Super Bowl XLIX in 2015, and the NCAA Final Four in 2017 to daily short-term tactical incidents have proven the capabilities of both the RWC as well as the regional interoperability processes.

The PSAP Intercommunications System

One of the most valuable interoperable resources in the Phoenix region is the PSAP Intercommunications System, often referred to as the “PSAP Channel” which links all dispatch centers across the region (both members and non-members) in a “party line” fashion. The PSAP talkgroup is only allowed in dispatch centers, never in mobile or portable subscribers and is utilized on a daily basis to request outside agency resources while also coordinating inter-agency communication and cooperation.

Technical Details

  • The RWC system is a 700 MHz Phase I/FDMA system that is in the process of migrating to Phase II/TDMA.
  • With system coverage of over 8000 square miles and over 4.5 million citizens (3+ million within the actual member jurisdictions), the system encompasses 15 cities and towns, 4 fire districts, a community college district, and supports 43 interoperable partners.
  • The Motorola Astro© 25 infrastructure supports primarily Motorola subscribers and consoles in over 20 dispatch centers but also allows competitive vendors on the system, especially popular in general government applications.
  • The system infrastructure consists of 53 tower sites, 7 simulcast cells, 975 simulcast channels, and over 200 dispatch consoles.
  • Currently there are 20,000 subscribers generating over 73,000 calls per day with an average system availability (lack of busies) of 99.95%, with an additional 20,000 subscribers used by the interoperability participants.
  • In 2018 there were over 28 million calls with only 131 busies, most of which went through on the second PTT.


The Phoenix area RWC system is a robust, well maintained, and highly reliable resource for day-to-day mission critical life safety communications. The sharing of interoperability resources, supported by the Phoenix Urban Area Security Initiative (UASI) as a cooperative effort across all public safety entities in the region, continues to play a vital role in interagency cooperation. One of the key elements of success across the Phoenix Region is the good relationships that are enjoyed across agencies both members and non-members. While the RWC system embraces state of the art technology, excellent operational and maintenance capabilities, excellent coverage for both local jurisdiction and wide area operations, it is this ability to come to the table and work together that is our most valued resource.



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


Stephen Nichols

Director Project 25 Technology Interest Group

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As a result of the P25 Executive Summit held in May 2018 in Portland, OR, the Project 25 Steering Committee established the Requirements and Priorities Working Group to develop a prioritized list of user challenges to be addressed through the P25 standards, increased user awareness, and/or manufacturer implementation. The Working Group spent the past year developing the requirements list and is requesting feedback from as many federal, state, and local public safety agencies as possible.

The Project 25 Technology Interest Group (PTIG) is collecting user feedback through the survey and will send results to the Project 25 Steering Committee to develop educational materials for users, establish new or update existing P25 Standards, or request manufacturer or user implementation changes.

To take the survey please click the following link

If you would like more information on the Requirements and Priorities Working Group, the Project 25 Steering Committee, or PTIG please send an email to This email address is being protected from spambots. You need JavaScript enabled to view it. or This email address is being protected from spambots. You need JavaScript enabled to view it..





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