Ok, because you were smart enough to specifically say what you hope to monitor -
a P25 Phase II system - that makes it much easier in the long run because there is only one current method of doing that with a personal computer and that means using OP25. Here's the basic gist of that:
If you want to use SDR hardware and software to
monitor P25 Phase II systems (or just one, if that's it) you're going to need to use Linux and by that I mean Ubuntu since that's what has been well established as the most favorable platform for using a software package known as OP25. OP25 allows one to monitor P25 Phase I and Phase II systems, trunked or conventional, using a personal computer (desktop, laptop, tablet, whatever but it needs to be running an actual desktop-class processor meaning not some mobile device in an ARM-powered tablet).
OP25 is a Linux-based software package and it's somewhat complicated in overall information but luckily because of a few really smart guys around here (namely KA1RBI and PiccoIntegra and of course a host of others who have shared their knowledge and experience on setting it all up) the process is at this time much much simpler than it used to be. In the past it required installing Ubuntu, then setting that up for compiling the GNURadio framework and compiling it (could take hours), then setting up and compiling OP25, then a lot of configuration edits, etc. A time-consuming and not always an easy thing to do and it absolutely was not done with a click or two.
Nowadays there's a more refined method that takes no more than maybe 30 minutes start to finish and you
can be up and running OP25 monitoring that new KSP 700 MHz P25 Phase II system, seriously.
It might be possible, depending on the hardware your computer has, to run OP25 inside a virtual machine (a guest OS) that's running on the host OS (Windows XP or 7, and I highly recommend Windows 7 for such purposes, XP is fraught with too many security risks nowadays and isn't going to get any better). There is an entire and very information laden thread about setting up OP25 in a virtual machine located here and it is well worth reading through regardless just so you can become more familiar with the terms and concepts:
http://forums.radioreference.com/so...-virtualbox-project-run-op25-windows-7-a.html
As stated and I'll repeat it:
the only current method available to monitor P25 Phase II (that's Phase 2) communications without a physical digital scanner from GRE/Radio Shack/Uniden/Whistler is using OP25 and that means using Linux, more specifically Ubuntu. There is no other method at this time of monitoring P25 Phase II - the hope is that the author(s) of DSD+ (a digital speech decoder) will be able to add P25 Phase II decoding support at some point in the near future but for now and probably well into 2017 there is no other way to do this. You can of course purchase a physical digital scanner to do it but you'll be looking at an investment of a few hundred bucks and you could theoretically decide it's not for you at a later time whereas an investment in SDR on the cheap end could cost you $25-50 tops (if you already have a computer and since you're online posting here at RR that's a given - I suppose you could be posting here from a smartphone but that's unlikely).
If you're interested in the specific tested method which I've used myself several times now and others have as well with practically guaranteed success (once you have the SDR hardware of course) you can find the very well laid out steps in this specific post here (it's in that same OP25 thread):
http://forums.radioreference.com/2654021-post764.html (the specific newly refined step by step installation method)
And again, I highly recommend you read through the entire thread to see how it's progressed since it was started, how many of us have made many attempts to get OP25 working in a virtual machine and do it well enough to get a proper understandable P25 Phase I or Phase II decode from the audio and nowadays with the newer methodology in that post above it actually does work quite well. It's still not as good as installing OP25 on the bare metal computer meaning not in a virtual machine but actually booting the physical computer into Ubuntu then running OP25 for that purpose but it does work well enough to use.
Long post, yes, I'm known for being wordy but I like to make sure I provide useful info even if I am a bit overly redundant sometimes.
Once you get rolling with SDR hardware and software it's a paradigm shift into an entirely new way of doing things: no longer are we limited to just being able to listen to what we're monitoring and in that usually just one frequency at a time but now we can see the spectrum visually and note activity when it's happening on multiple frequencies inside the visible spectrum (given the bandwidth capability of the hardware you're using) and tune to them with a click
and a whole lot more.
Hope this info helps, pretty sure you'll love doing things in this "new" way once you get into it, and as always, RR is a place for learning and sharing so by all means if you have questions ask and if you have answers for others when you get more experience then don't hesitate to help when you get the chance.
Happy New Year, as well.
