Well this has been a long time coming since we first tweeted about it on February 29th, 2013! Due to work restraints it’s taken nearly a month to get this out to those interested and to be able to find a format in which to present it.
We finally managed to sit down a few weeks back and commence mapping who uses what frequency on the MMR Network. As many familiar with the network would know the voice frequencies are partitioned, that being that each service has its own frequency set aside within the system for its talk requirements.
Obviously not all towers, well actually nowhere near all of them, have been mapped as of yet. That is going to take a fair amount of time and hopefully some input from those able to assist in this exercise.
A few interesting observations regarding this exercise so far.
A network user whose radio sends data tends to use a ‘talk frequency’ from another agency in order to do so. We’ve noted that if an Ambulance radio has a need to send data packets it will use a ‘talk frequency’ from those set aside for Police or Fire, never one of its own. On the other hand if a Police radio has a need to send data packets it will do so on a talk frequency set aside for Ambulance or Fire and so on.
For those wondering how we obtained these results we used a UBCD396XT and ran the Pro96Com software with it in order to decode the P25 control channel data on each of the system towers completed so far.
The program is available here for those interested and would like to have a go themselves; http://www.psredit.com/pro96com/
The results completed so far are available under the sites MMR Network menu. We’ll try to complete other sites as results come to hand. The plan is to have each site on its own page and in numerical order.
Anyone who has the ability to assist in this exercise feel free to drop us a line for an explanation of what’s required.