A book about the war in Iraq had an brief passage about an Army Unit that needed to stop, dismount, and reset their frequency because they were getting stepped on by a marine Corp unit using the same freq. The Marines were in contact and were not about to change Frequencies. This lead me to thinking about a way to solve this problem via network protocols and public/private key exchanges.

Each unit has a radio. These radios already can encrypt traffic and frequency hop. In fact, frequency hopping would have prevented the unit from getting stepped on. But let’s assume that freq hopping is out of the picture for now. Instead, we want to set up a protocol where a unit can reassemble on the network without having to expose itself and meet face to face.

1. Each machine would get a private key. This allows it to be uniquely identified on the network.

2. Each machine gets a list of public keys and their assigned units (a heads up display could then show who was talking, removing the need for “Black 8 this is Black 6 over.”)

3. A set of frequencies would be set aside for meta-data commo. I’ll call this the MDF. The MDF would be shared by all units within a theater of operations, and would be redundant. Just like name servers, a radio would get a list of MDFs to try. Thus four MDFs could be assigned, and four units would get a different MDF to use as it’s primary.

4. The radio would monitor both its main frequencies (the Radios I used when I were could monitor two, I assume the new ones can do better) and the MDF. MDF traffic would all be binary data. Listening to it would be like listening to a 300baud modem.

5. A “Lost” Unit would broadcast a connection request on the metadata frequency. Any other unit in the area could answer.

6. Higher would send down the new frequency using the lost units public key.

7. The lost unit’s radio would set the new frequency and drive on.

One glaring weakness is that the MDF itself could be jammed. One faulty radio could crap-flood the frequency.

It also adds overhead to the whole system by removing frequencies that could otherwise be used. An optional interactive authentication step could provide for the soldier entering a pin or password if there is some question of the radio being compromised. Two valid response could be provided, one that means , “I’m me” and one that means “I’m me and doing this under duress.”

Note that none of this would prevent manual resets, just provide an additional capability for automated resets.

Of course, this is yet more electronics subject to the beating an infantryman gives it.

Update:  Of course the Military is way ahead of this.

http://en.wikipedia.org/wiki/AN/PRC-148

And

http://en.wikipedia.org/wiki/Joint_Tactical_Radio_System