wearing a war suit...

I really do post date the Smoke Signals and even the Telegraph and Heliograph.

...Barely...

However, I'm old enough that radio was the primary comm means and we did back then turn 'em off for training and for real when our emissions might have been a problem.

There was no replicate to it, the idea was not to find alternatives or substitutes, it was to do the job without using them at all. Hard as it is to believe with all the modern gee whiz stuff, GPS, BFT, etc. (those are just aids -- and that's all they are, aids, they are not imperatives) and amazing as it may seem that units were trusted to the extent that they were released from view and 'positive control' to perform actual combat missions in a fairly active war or two, it was done. You can really do that...

One would be remiss to not understand that even if non use of comm and the other aids was not intentional it did, does and can happen due to both technological and logistic problems -- and even more frequently as a result enemy or combat action. Combat is hard on equipment...

The problem is that we are not using our aids as aids-- they are too often being used as substitutes for a lack of training. They have ceased being a cane and have become a Walker (or even a Wheelchair in some cases...) That's what Mattis is warning against...