Project 25 Technology Information Group

Monday, June 25, 2018

Project 25 Technology Information Group

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County, Iowa (county seat of Iowa City and home to the University of Iowa) released an RFP in 2008 to replace their outdated analog 800 MHz trunking system with a P25 system.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



P25 system of the month

Government Wireless Network | Queensland, Australia


Government Wireless Network

The Government Wireless Network (GWN) provides public safety agencies with a fully integrated, secure digital radio communications network for mission-critical voice, radio and data communications across the greater Brisbane and South East Queensland region in Queensland, Australia.

Operating in the 400MHz Harmonised Government Spectrum – specifically the 420-430MHz frequency band (Band 5), the network brings agencies onto the same radio communications platform to assist in improving the efficiency and effectiveness of frontline operations.

Queensland is adopting Project 25 (P25) Phase 2 technology for the GWN. Utilising P25 Phase 2 technology, the network provides the highest levels of radio communications availability, reliability, security and clarity via a fully fault-tolerant architecture.

The Queensland Government, Telstra Corporation Limited and Motorola Solutions Australia have formed a successful partnership to design and deliver a secure, fully integrated government radio communications network.

Full implementation of the GWN and operational transition of Queensland’s police, fire and ambulance services will be completed by June 2016. When complete, the network will service more than 17,500 frontline police and emergency services personnel in South East Queensland.





The Queensland Department of Science, Information Technology and Innovation is delivering the GWN in partnership with Queensland Police Service, Queensland Fire and Emergency Services and Queensland Ambulance Service to ensure the solution meets operational requirements and fully integrates with other dispatch systems. 

Telstra Corporation Limited, with its public safety strategic solutions supplier Motorola Solutions Australia, is responsible for the design, build, financing, operation and maintenance of the GWN under a 15-year managed service agreement with the Queensland Government.  

Mingara Australasia is the Queensland Government technical advisor for the GWN and their extensive experience in specifying, planning and delivering similar radio communications networks in other Australian and international jurisdictions has been a major contributor to the success of the GWN. 

With a total contract value of $515 million, the GWN is one of the largest public sector ICT ‘as-a-service’ arrangements currently being delivered in Australia. 


GWN for the G20


The Brisbane G20 Leaders’ Summit held in November 2014 was the largest peacetime security operation ever held in Australia. The network played a vital role in the G20 by maximising public safety agency response capability and providing secure and interoperable mobile radio communications.  

The GWN set a new Australian benchmark in inter-agency interoperability, encryption and frontline officer safety. About 9,750 Queensland police, fire and ambulance personnel and 500 national and international security specialists relied on the GWN wireless capability to ensure the safety of 20 world leaders, 43 international diplomats, 4,000 delegates and 3,000 domestic and international media, as well as the general public and issue-motivated protest groups.  


South East Queensland implementation


The South East Queensland implementation of the GWN is the largest single deployment of Project 25 Phase 2 technology in the world, with 179 radio base station sites built and commissioned. 

The GWN provides 99% coverage of the South East Queensland population across an area of 30,000 square kilometres stretching from Tweed Heads in the south, Oakey in the west and Gympie in the north. The extensive coverage of the GWN provides public safety agencies with vastly improved radio communications reach into the community.  

The GWN is being delivered in stages with full implementation of the network to be completed by June 2016. A staged approach means implementation is more manageable for public safety agencies, particularly from a training and organisational change perspective. 

A close and productive relationship between the Queensland Government, Telstra and Motorola, and public safety agencies has allowed for the seamless flow of deliverables and interdependencies. As a result, operational transition to the GWN in stages 1 and 2 has been a resounding success.  

For a project of this size, scale, complexity and importance, highly effective planning, good operational readiness and an integrated approach have been key factors of its success. 


ISSI and CSSI interface


The GWN has been equipped and licenced with a range of P25 features and functionality, however two key features have been provided to facilitate interconnection to external P25 systems and consoles. These are the ISSI and CSSI interfaces. As the CSSI feature set is predominantly a subset of the ISSI, GWN testing of the ISSI interface was also seen as satisfying the CSSI testing requirement. 

The GWN is provided with an off-line facility or ‘sand pit’ which fully replicates the production system and hence non-disruptive ISSI interface testing with third party P25 systems was able to be tested. This testing was successful, however the process proved invaluable as it highlighted a large range of network configuration settings, terminal ID requirements and P25 feature sets that need to be known and set up correctly before ISSI links can be permitted between two or more P25 production network. These lessons learned are invaluable and can be used to assist mitigating any connectivity risks into the future.  


Network scalability


The network and contract has been designed to be scalable to allow for the expansion of GWN coverage and capacity to other locations in Queensland and to other users. 

There is potential to expand the GWN to allow other government agencies, such as the State Emergency Service, and local government to use it. However, at this stage, the government has only committed to deliver the network for Queensland’s public safety agencies operating in South East Queensland.


A copy of this Article can be downloaded using the link below:


Queensland Australia P25 System of the Month










The Project 25 Technology Interest group is releasing a P25 Standards Update report from the most recent TIA TR-8 meetings held in late January in San Diego California


This report is authored by Andy Davis the Chairman of TIA TR-8  The report highlights TR-8 accomplishments and work in progress for 2016. The document will be updated after every TR-8 face to face meeting occurring in 2016. The filename reflects the date of the latest update. After the first 2016 version, each update will use blue font to indicate the updates.


The report can be accessed using the link below:


P25 Standards Update January 2016






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