Trunk recorder is able to record the calls on a trunked radio system. The apco p25 decoder then appears as an additional window. P25, or project 25, is a suite of standards developed to provide digital voice and data communication systems suited to public safety and first responders. Icom is selling the pcr2500, a black box computercontrolled receiver. Tait p25 portable radios are designed and built to withstand the challenging conditions public safety users operate in. The software is being expanded into a decoding suite that can gives various bits of information about a received signal and there is also provision for a. The stock rtlsdr dongle antennas worked fine for me. Apco project 25 p25 was developed by joint efforts of the association of public safety communications officials international apco, the national association of state telecommunications directors. Aug 21, 2016 ive searched the forums, but have found lots of conflicting information as to whether sdr and the supporting programs can actually pull in and decode p25 p2. To me there is something wrong when a company sells a apco p25 decoder that needs to be tuned within 500 hz for it to work and it is only yes, only a software option for the 305 series receiver that can drift 8000 hz on the most popular band for p25 800 mhz. Btw, i thought my scanner decoded apco 25, but i guess they. Project 25 p25 or apco 25 is a suite of standards for digital mobile radio communications designed for use by public safety organizations in north america. With the optional ut112 p25 digital voice decoder, the pcr2500 is able to decode but not track apco project 25 transmissions.
This is the perfect project to get your feet wet in linux. With every transmittion from a p25 radio, metadata with the unit id, talkgroup id and nac network access code since the message is sent via broadbast. Digital protocols like apco 25 may be used with either conventional or trunked radio systems. It uses 1 or more software defined radios sdrs to do. However, it is important to have a good plan in place to ensure communication stays secure and the administrative overhead of managing the radios is in line with the level of security required. The apco p25 decoder then appears fully integrated within the receiver front panel. I will submit the op25 decoder grc block, desofb decryption support and other enhancements to the op25 project soon. It also works on other digital modes but i have not yet tried. Pdf a softwaredefined radio receiver for apco project 25. Super cheap software defined radios such as the rtlsdr can be used to decode these digital voice communication signals instead of expensive radio scanners. Researchers based at the university of pennsylvania have published an academic paper describing some security weaknesses in p25. For example, software radio approaches can receive many channels at once, handle both voice and data including the trunking control channel, decrypt encrypted traffic when the key is known and. Uniden is selling the sds100 handheld and sds200 basemobile scanners.
The apco p25 decoder window consists of the following main parts. In summary, p25 makes it very easy to add encryption to a radio system. Nov 05, 2007 likely it is because i and scott are the only ones to buy the apco p25 option so far. Op25 started as the thesis for a computer security phd student that is researching the security aspects of the apco25 standard. One contributor is also working on adding transmit code with the intention of giving a software based p25 repeater that can be run off. The sdrs capture large swatches of rf and then use software to process what was recieved. Digital speech decoder and xmbe codec library to decode various xmbe based, qpsk, c4fm modes such as p25 phase 2 tdma, mototrbo, provoice, nexedge and others. Apco project 25 p25 radio frequently asked questions tait.
Apco project 25 p25 is a suite of wireless communications protocols designed for public safety twoway voice radio systems. Covers usa and canada, quick record and playback 4. P25 trunked tracking and decoding with rtlsdr, unitrunker. The only things that do phase 2 are hardware scanners and hardware radios. Likely it is because i and scott are the only ones to buy the apco p25 option so far. A simple tuner app for linux and mac osx and maybe bsd. Tutorial on setting up op25 for p25 phase 2 digital voice. It allegedly also uses the p25 format and was a popular calculatorlike toy back in 1994.
Multiple radio systems can be recorded at the same time. The unit id is a 25 bit code that is more the most part unique to each radio p25 radios tend to respond automatically to any ping that it comes across. Monitoring apco project 25 systems requires a digitalcapable scanner. The frequencies can easily be received with an rtlsdr, but a decoder is required to be able to actually listen to the voice. Just plug it into your pc usb interface which is also used to power the decoder unit, install the software and enjoy the world of digital transmission decoding. Digital police scanner p25 apco digital radio scanner. To decode more than one voice transmission, increase the number of dongles needed. Digital speech decoder is an open source software package that decodes several digital speech formats. Decoding apco p25 voice via discriminator tap on rs pro163 using digital speech decoder software. I would like to let you guys know about an open source p25 decoder analyzer project that has been running for a little while now. Security researchers crack apco p25 encryption slashdot. There are some references to breaking encryption on a p25 system that i have come across. P25 control channel decoding i want to decode the control channel for the p25 network where i live.
Ive searched the forums, but have found lots of conflicting information as to whether sdr and the supporting programs can actually pull in and decode p25 p2. You can read the paper in pdf format here local copy here. Hardware scanners such as the uniden bcd996t offer apco p25 functionality but software defined radio sdr offers significantly improved flexibility. P25 radios are a direct replacement for analog uhf typically fm radios, but add the ability to transfer data as well as voice, allowing for more natural implementations of encryption. Uniden homepatrol2 color touchscreen simple program digital scanner, trunktracker v and s,a,m,e, emergencyweather alert, apco p25 phase 1 and 2. Project 25 phase 2 tdma decoding in software works over a year ago, i started worrying about what would become of my softwarebased scanner site after the county built their new radio system. The apco p25 decoder is an xrs plugin which, upon installation, can be selected from the receivers plugins decoders top bar menu, as simply another alternative demodulator. This apco p25 decoder plugin makes it possible to receive and listen to digital apco p25 phase 1 channels on winradio wrg305 series receivers. It converts your analog receiver if equipped with a 10. Both are capable of monitoring p25 phase 1 and phase 2 systems and are the first consumergrade scanners based on softwaredefined radio sdr technology. Whereas my existing work from 2011 worked on a motorola smartnet system with regular analog fm audio channels, this new system would be p25 with tdma. The apco p25 decoder is an xrs plugin which, upon installation, can be selected from the receivers demodulators top bar menu, as simply another alternative demodulator. One contributor is also working on adding transmit.
The aor ard25 can decode apco 25 digital signals excluding encrypted signals. Hardware scanners such as the uniden bcd996t offer apco p25 functionality but softwaredefined radio sdr offers significantly improved flexibility. Level up use uniscope to find the right recording levels. Even if i had a physical computer with usb, price is a large limiting factor in this. A free and open source decoder for digital mobile radio dmr is available here. Jun 24, 2012 decoding apco p25 voice via discriminator tap on rs pro163 using digital speech decoder software. It uses the mbelib library a separate open source package to synthesize the decoded digital speech.
If its truly encrypted voice your ability to crack the crypto is probably going to be quite an undertaking. Apco p25 decoder plugin for wrg315 series receivers. Apco project 25 p25 is a digital radio standard that has been specified, in conjunction with the public safety community, to meet the needs of the public safety community, such as interoperability. Its not the easiest software to install or use but if your into scanning and just even wondered about linux. Software like sdrtrunk and dsdplus can decode p25 phase 1, but at the moment the only software that is capable of decoding p25 phase 1 and 2 is a program called op25. Apr 11, 20 the most common digital speech codec is apco p25, which dsd is able to decode. Dsd is also capable of decoding other common digital codecs such as dmrmototrbo, nxdn, dstar and provoice. But nowdays an inexpensive sdr software defined radio that can be used to receive police, fire, federal, and other digital radio transmissions. Pro96com control channel decoder for p25 trunked radio.
P25 radios are a direct replacement for analog uhf typically fm radios, but add the ability to transfer data as well as voice, allowing for more natural implementations of encryption and text messaging. Packed with a range of safetyenhancing features, our p25 portables provide the clear audio, reliable connection, and interoperability that those serving our communities depend on. I gather that the hardware dongles, such as offered by noo, can accommodate the frequencies, and that it comes down to the software. Pro96com for monitoring p25 systems with a pro96 or psr500600. The winradio wrdrd172 apco p25 phase 2 decoder is a smart and handy decoder dongle that provides a hardware codec for single channel reception of apco p25 digital transmissions. The protocols include security options in which voice and data.
Project 25 was initiated by the association of public safety communications officials, or apco. P25 digital voice decoding with gnuradio op25 project. Add a rolling encription code, then the system has to decode each time. Pro96com control channel decoder for p25 trunked radio systems. An anonymous reader writes two australian security researchers, stephen glass and matt robert, have published a paper that details flaws in the encryption implementation pdf in the apco project 25 digital radio standard, used by emergency services and police departments worldwide. Op25 is a program that decodes p25 phase 1 and phase 2 digital radio. Aug 04, 2014 project 25 phase 2 tdma decoding in software works over a year ago, i started worrying about what would become of my software based scanner site after the county built their new radio system. In the case of attempting to run a virtual private server providing an analog to digital dmr bridge using the dmrgateway software, i couldnt procede any farther until i plugged a usb fob with the vocoder chip which is completely impossible on a virtual server. This idea was first asked on the batlabs message board in a thread about tims maxtrac p25 mods. If ricks nac decoder included his source code it would be possible to add code to have the program change the logic status of a parallel printer or serial port pin on the computer which could be used for a cor input to a repeater controller. Ive uploaded a video showing up how dsd works with apco 25 p25, project 25.
The pcr2500 is not able to track any type of trunked radio system. Via dangerousprototypes written by admin 6 comments posted in applications, digital signals, news tagged with apco, digital speech decoder, dmr, dsd, gnu radio, mototrbo, p25 april 11, 20. Apr 05, 2012 i will submit the op25 decoder grc block, desofb decryption support and other enhancements to the op25 project soon. The libraries from the amazing op25 project are used for a lot of the p25 functionality. It does not allow decoding of encrypted communications. Btw, i thought my scanner decoded apco 25, but i guess they mean the digital encoding overlaid on top of apco 25. Dsd is a linux and windows software program capable of decoding popular digital speech codecs such as apco p25 and mototrbodmr. Project 25 digital radios law enforcement grade vulnerable. Im not interested in audio, just the control channel i want to. Be prepared and able to communicate in case of emergency with the largest selection at. Some municipal areas are upgrading to p25 phase 2 so almost gone are the days that you can track them with a police scanner since p25 is a trunked radio system and not just a lone frequency to monitor. Project 25 p25 or apco25 is a suite of standards for digital mobile radio communications designed for use by public safety organizations in north america. Digital protocols like apco25 may be used with either conventional or trunked radio systems. Download digital speech decoder and mbe library for free.