CBTL,
I hadn't intended to be patronising, but I was perhaps teasing you slightly. You asked about transponders and I answered that question for you.
You then said that your question was about actually TCAS or similar collision avoidance equipment. I assume you fully understand the difference but you haven't indicated whether you are a pilot or not.
However, all licensed pilots (especially military trained) do, or should, know that today's collision avoidance devices cannot replace proper lookout, and conversely, human lookout is very much imperfect in the airborne environment. That's why it's a requirement to maintain a good lookout, using TCAS or similar when available to merely assist with visual acquisition of other aircraft.
The problem with remote controlled aerial devices is that they are usually very difficult to see due to their small size, they often move erratically and unpredictably and they do not operate with regard to the principle of see and be seen, or the rules of the air with regard to right of way, which are legal requirements for aircraft operating in the open FIR.