I know, it's only a combination of the earlier proposals, but I think that the HF/VHF-spectrum of the Truppenfunk (which is divided into HF=mostly signal and VHF=mostly voice) deserves that "comprehensive" term - and imho it combines both aspects: equipment & communication/message/etc.
In former times it would have been sth like battlefield coms but these terms are not accurate/correct any longer.
And - I chose the lowest confidence level.

Back in my day we were still using the abacus, the "Kernrechner" and suchlike hadn`t been invented yet! But where radios were concerned (they had been around for quite a while!), anybody working with them was employed with `signals´:
"Signaller" - someone trained to operate a radio
"Signals Platoon" - the subsection within a company responsible for radio communications, and where the "signallers" were employed,
"Royal Signals" - the corps responsible for radio capabilities army-wide,
"QMSI Signals" - designation for the head honcho in a regiment who is responsible for signals equipment and training.

Towards the end of the 70`s, with the emergence of "managementspeak", the terms `communications´ and `comms´ were starting to come in vogue. They are probably still around as well, so you have a difficult choice before you!


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Note added at 1 day2 hrs (2009-02-26 00:09:57 GMT)
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With regard to your clarification request:

I take it you are working on a document for or from the Austrian Armed Forces? Perhaps something to do with this? -

www.bmlv.gv.at/ausschreibungen/show_sach.php?id=781

From my brief Google research it would appear that the Austrian is the only military force in the Germanic speaking world using the terms "Truppenfunk" and "Gruppenfunk". As they were not, and still are not, a part of NATO, it may well be that the command structure of their military force is somewhat different to that of other countries. This makes the search for translations of Austrian military terminology that accords with that used in other armies a tad difficult!

In practice, military signalling/communications is quite easy - it is nothing more than the passing of orders and information, either up the chain of command or down it, as quickly as possible. The bods at the top and bottom of the chain of command tend to only have one radio, those in between have two, on different frequencies, thus:

1 Radio, for the link Platoon - Company // 2 Radios, the second for the additional link Company - Battalion // 2 Radios, for the additional link Battalion - Brigade // and so on until you arrive at the top of the chain, where Army HQ only talks to Corps HQ. It`s just not on for a Platoon Sergeant to talk directly to Division HQ - it could adversely affect promotions for the field officers in between!

Now, could it be that "Gruppenfunk" is the sigs network at the higher command level and "Truppenfunk" the sigs network at the subordinate command level? I would be inclined to ask the client how these two terms relate to the command structure, if at all.

Alternatively, this might all have something to do with the new-fangled systems I`ve heard of where each individual soldier (Truppen?) is `wired-up´ with his own radio and in direct communication with his next superior command (Gruppen?). If so, it could well be there is a new terminology for it all, even in the British forces (and, of which I am now not aware!).