Project 25


Hello everybody and welcome back to Everything Hamradio! This month we have been talking about digital voice communications with a little bit of digital data thrown in the mix. We have talked about DStar and Yaesu System Fusion, but today we are going to talk about something a little different. With our last two modes, it was for amateur radio, today’s topic, while it is a digital mode, it is for the public safety organizations. Namely, we are going to be talking about Project 25 or P25 for short.

What is Project 25?

The P25 is the public safety version of Yaesu System Fusion, I would say. It will do both analog and digital communications and uses the same C4FM protocols. The official answer to this question as it says on the Project 25 website is:

Project 25 (P25) is the standard for the design and manufacture of interoperable digital two-way wireless communications products.  Developed in North America with state, local and federal representatives and Telecommunications Industry Association (TIA) governance, P25 has gained worldwide acceptance for public safety, security, public service, and commercial applications.

The published P25 standards suite is administered by the Telecommunications Industry Association (TIA Mobile and Personal Private Radio Standards Committee TR-8).  Radio equipment that demonstrates compliance with P25 is able to meet a set of minimum requirements to fit the needs of public safety.  The P25 standard was created by, and is intended for, public safety professionals.


Now that we know what P25 is, let’s talk a little bit about how it came about. The move to P25 has been a long journey and it really didn’t move very fast until after 9/11/2001. Back in 1980’s, public safety learned that is was getting harder and harder to communicate between other agencies and to be able to work together because of it. If department A had a tornado go through their town and department B came over to help but they couldn’t talk to anyone from Department A, it really made things tough. During some of the disasters in the 1980’s, agencies really had to face reality that something needed to change.

In 1988, at the direction of the United State Congress, the Federal Communications Commission(FCC), initied an inquery for recommendations from users and manufacturers to improve existing communication systems. In October 1989, APCO Porject 25 came into being in a coalition with :

During the 1990’s, agencies were slow to move to this new system. One of the reasons, was that it was incredibly expensive! Hand held radio’s were 2000-3000 dollars!! Conventional analog radios could be bought for 600-900 dollars. Mobile radios were even more than that. Then on top of the radios for every vehicle and officer, you have to have a repeater and a connection to the backbone of the P25 network. Even for small cities with only a handful of officers and vehicles, this could still be $250k easily. Can you imagine the cost to a big city?!? About 5 years ago, my local sheriff’s office went to P25. With all the equipment that they had to buy it ran somewhere in the neighborhood of 5-8 million dollars! Prices have since come down quite a bit from what I understand, so that is a good thing.

I think money was probably the biggest factor to why it took so long to transition over to the P25 systems. Then again, there is the mindset of, “If it’s not broke, don’t fix it!” I can see and somewhat agree with this, especially for those agencies that are out in the middle of no where. Here is the thing though, after 9/11 and the formation of Homeland Security, changes came about that make it where you pretty much have to go to P25 in one way or another to get any kind of government support.

A few years after 9/11, the NIMS system was implemented and one of the major points in the NIMS system is interoperability. So a deadline was given out that if a department wasn’t on the officially adopted system of P25, they would not be eligible to receive any assistance or grants from the federal government. During this time frame, and probably even now, an agency can apply for grants to help them migrate to the P25 system though.

Pros and Cons

Much like the features that they Yaesus System Fusion and DStar systems have, so does P25. It has the clearer audio quality, the digital ID, the automatic location functions, and data transfer functionality. Even though it has all this, it was, and possibly still is, very susceptible to interference of the intentional kind. There has been several studies down where they have found the the P25 system has a major flaw in it’s security.

One of the reports stated that the the DES-OFB and Motorola’s proprietary ADP ciphers were vulnerable to brute force key recovery. Another report stated that the radios were hard to use and hard to tell when they were in open or secure modes making where they heard some transmissions of the confidential nature come across in open air. This report also said that a signal radio could be jammed or tracked with a modified child’s toy that cost only $30! There were a couple reports that stated that a P25 radio could be jammed very easily with only a fraction, 1/25 to be exact, of the power that was being transmitted from the P25 radio.

With all this being said, all of these reports were presented in 2011, so changes to the system have probably been made by now, but that is unknown to me. I would hope that this would’ve been fixed sometime in the past 5 years! Especially since I am a 911 dispatcher and it is part of my responsibility to get my officers home safely!


You didn’t say how P25 was used in amateur radio. That is correct, I did not, because it is not used in amateur radio. The P25 system is used primarily in the public safety fields and somewhat recently in the private organizations. It is also, mainly used in the US, however it is used in other countries like Canada, Australia, and Russia along with about 60 other countries as of 2004.

Even though P25 is not used in the Amateur Radio community, it does mirror us in some ways and I thought it would be good to at least talk about it a little bit since it is one of the major digital voice communications modes out there. We have one more digital voice mode to talk about, Digital Mode Radio(DMR). We will talk about it on Thursday.

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Until next time…

73 de Curtis, K5CLM

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