Interesting you just put up an article dealing with Inter-team comms. I just finished putting together a spreadsheet app that helps a comms guy with the more tedious portions of assembling an SOI. I’ll attach it here following the write-up.
Having acquired a set of DMR radios, and then others I know having done the same, I had to try to come up with an easier way to integrate new radios into our “Plan.” I had also noticed that a number of other groups – including a larger “organization” – had neither the knowledge or experience to assemble something that would meet their requirements. (Newer organizations seem not to realize where they might be lacking.) Given the current situation, I set out to provide a tool that might help. Here it is. Feel free to use or not use it. To change, edit improve, (or ruin) it to your hearts content.
* ALWAYS test that operation of the radios are as desired following programming and before operational use. * YOU are responsible for the final product and anything that goes awry.
Developing an SOI (Signals Operating Instruction) can be a time consuming task. One of the more tedious parts of writing a SOI is the assigning of frequencies and even more so any associated parameters particularly for channels, especially if using digital radios. To make matters harder, good ComSec (Communications Security) practices would include compartmentalization (only those who need to know a particular piece of information are given that information,) obscuring the transmission (e.g., through use of directional antennas,) obscuring the message and frequent changing of the SOI.
The attached spreadsheet helps mitigate the problems of creating appropriate sections of the SOI, making it easier to change the SOI more frequently, compartmentalizing relevant parts of the SOI and obscuring the message when the radios are capable of encryption. While the spreadsheet is optimized for the Baofeng DM-1701, it can be adapted for nearly any radio(s). It is also designed to provide examples of many types of communications “networks.” As it is, it is likely more complicated than most will have need for. However, a small amount of analysis of it should lead the aspiring SOI writer to see how to expand its use fairly easily to an even larger “Command Structure.”
“Command” Structure of the Radio Network as used in the SOI Spreadsheet:
X
    /  |  \
P Q   R
    /  |  \
  A  B  C
        |     |     |
A1  B1  C1
X Battalion Commander
P/Q/R Company Leaders
A/B/C Squad Leaders
A1/B1/C1 Assistant Squad Leaders (or #2 Team Leader) – These are not specifically listed in the spreadsheet, instead referred to indirectly on Sheet 1 Intra-Squad Channels (3 and 4, for Columns A, B, C.)
Not everything in the spreadsheet need be used. It is easier though, not to utilize unneeded portions than to add them in, so I included more than most would likely want. The ability to set up both analog and digital is present. Organizing encryption keys, color codes, CTCSS tones, separate transmit and receive frequencies are all present. Just place the desired parameter in the proper block of Sheet 3 (the variables page) and the parameter will be automatically populated into the proper positions of Sheets 1 & 2. You can rename the variable names on any page to anything you like without affecting the spreadsheet’s operation if you want to make something more clear. However, if you re-arrange locations of the actual value-cells, things will run amok. (Adding or removing columns or rows does not seem to make a difference though.)
You can mix and match parts depending on your circumstances and hardware. For instance, you are Platoon Leader. You have 1 Squad of two Fire Teams and an Overwatch. The Squad has two UV-5r radios (1 per team, Squad Leader and Assistant SL.) Platoon Leader and Overwatch each have a DM-1701. You can count the Overwatch as a separate squad OR as part of the squad. Given that he has a DM-1701, it would likely be better to count as a separate squad. PL and overwatch then talk on digital, but if part of the squad would be limited to analog. PL and SL talk on analog. SL and ASL talk on analog. If each of these communication links is limited to only two parties total, then each link could have separate Tx (transmission) and Rx (Receive) frequencies. Overwatch could monitor (or even talk to) the SL/ASL also, but that would require a small bit of adjustment or “adapting” a different channel on the spreadsheet to fit this arrangement.
(It would be good to know how scanning on your radio works, so that you are not necessarily limited to only monitoring two VFOs, depending on your circumstances.)
The only items to enter directly into Sheets 1 and 2 are for Channel Name. This is left for the individual users/radio-programmers to set up however seems fitting to them. Likewise, Channel Numbers are arbitrary and can be changed. They are only here to make it easier to find a section and correlate between sections. (e.g., Channel 11 for the Platoon Leader has all the same information on each of the two Sheets.) Many radios do not allow the user to set a channel to a specific number without lots of handwaving and incantations. Be forewarned.
You can change the notes to whatever you like without repercussion. A lot of them may appear esoteric as they are. They are there for me.
For the mere minimal squad (two fire teams of two) Sheet 1 is overkill (let alone using Sheet 2.)  Adding a second squad to the mix can complicate things quite a bit especially if you want to maximize ComSec risks. Adding a third squad (and the necessary Platoon Leader) make the requirements even more complicated. That’s where Sheet 1 really helps. Expand to two platoons and you just use Sheet 1 twice and also Sheet 2. Ditto for another platoon. A second company requires two Sheet 2s. Just make appropriate changes to the additional sheets used as applicable. You get the drift.
Don’t get hung up on the values I have entered into the sample spreadsheet – they are there for testing, and so that you can easily see what parameters in one radio correlate to parameters in another radio. You may not like the order or arrangement that I have the variables in on Sheet 3. Too bad. It annoys me too, but I can live with it. See my warning above regarding changes.
This does not include anything for repeaters (tactical or otherwise.) That’s up to you if you feel the need.
I am NOT advocating using parameters that might be contrary to the laws of your jurisdiction.
Note that this is not an instruction on how to program your radios or detail the use of the CPS (Code Plug Software.) This helps organize information for you to enable easier programming of your radios with whatever software you use or from the radio face if possible. YOU have to know how to set up a contact list, group list, etc. for better utilization of text messaging or any other features your radios may have.
Here are some additional notes that you might find helpful:
General note regarding DMR:
For a simplex radio in a normal DMR mode, the radio will receive calls from either timeslot. The transmitting radio can change which slot it transmits on, there is no need for ‘sync’ as there is only one data stream. The radios normally lock into whatever slot they hear as active, if there is an irrelevant call comes in on slot 2 then the radio will not hear a relevant call on slot 1 while both are happening. You can even see this in the CPS software, you can always select the slot in simplex.
Uniden’s Close Call doesn’t pick up the transmission, because Close Call requires a continuous TX for more than 30ms to trigger a hit. DMR transmissions are 27.5ms out of every 60ms.
However, transmissions CAN be picked up IF the frequency is programmed in as part of a scan list. The scanner will display a lot of useful info for the listener. Because the above information can be scanned, it is IMPERATIVE that the radio ID and “custom” Talk Group IDs be changed EVERY Mission/Op, or else a partially competent SigInt guy will be able to correlate personnel/teams/you-have-its from op-to-op. Also, an operator should NEVER utilize one of these as a “typical” DMR radio attached to the net with their personal 7-digit radio ID as this would positively correlate the radio with the operator through their FCC call sign. That would be…bad juju. Don’t be that guy.
Notes Specific to DM-1701:
Avoid having same channel selected on both VFOs – seems to get goofy/inconsistent on whether comes in on A or B, and sometimes results in funky non-transmission/receipt of messages.
DO NOT enable *Privacy On/Off* key – will default to [Basic 1 Key] upon re-enabling. Just set to On in menu for channel. (Unless, of course, you want it to just use Basic 1 encryption.)
Text Messaging DOES NOT utilize encryption! I have tested this with the latest CPS and Firmware with my set of 4 radios, setting all radios equally with the exception of 1 having encryption not enabled on the channel. Voice transmitting encrypted only is decrypted on the radios with encryption enabled. SMS transmitted from encryption-enabled radio IS STILL successfully received on the radio without encryption enabled. In support my findings I note the following:
[From Radioddity.com (the primary supplier of the DM-1701 for Baofeng) and repeated at the Top-10 evaluation at https://www.myaudioplanet.com/the-best-dmr-radios/
“Strong Digital Function – …encryption only supports calling between the DM-1701 devices…”]
Enable/Kill works without encryption – if Color Code matches (or None if CC# is set to None) then can be killed. Attacker must know Radio ID and CC#. CAN BE DETERMINED via scanning (e.g., DSD on Linux w/RTL-SDR, or Bearcat 436/536.) Have not fiddled with the analog DTMF option for it, as would require receiving radio to be on an analog channel which would probably be rare, especially of radio was “compromised.” Summary: don’t enable the Kill function. Was neat, but a partially competent SigInt guy will screw the team over by trying to kill the radios, so don’t tempt him.
Battery Release needs a block/stop of some kind to prevent accidentally dumping power to the radio when grabbing it. Easy fix.
Sometimes the volume knob seems to stop really low. It’s the bumps on the volume knob stopping against the left (selector) knob bumps. Turn harder.
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