AHRENS: The signal regiment of an army group had the task of setting up and maintaining communications between the army group and the neighboring units and subordinate units, as well as preparing the necessary lines of communication for new operations.
DR. STAHMER: Did your regiment have any special tasks apart from that?
AHRENS: No, with the exception of the duty of defending themselves, of taking all measures to hinder a sudden attack and of holding themselves in readiness to defend themselves with the forces at their disposal, so as to prevent the capture of the regimental battle headquarters.
This was particularly important for an army group signal regiment and its battle headquarters because we had to keep a lot of highly secret material in our staff.
DR. STAHMER: Your regiment was the Signal Regiment 537. Was there also an Engineer Battalion 537, the same number?
AHRENS: During the time when I was in the Army Group Center I heard of no unit with the same number, nor do I believe that there was such a unit.
DR. STAHMER: And to whom were you subordinated?
AHRENS: I was directly subordinated to the staff of the Army Group Center, and that was the case during the entire period when I was with the army group. My superior was General Oberhäuser.
With regard to defense, the signal staff of the regiment with its first battalion, which was in close touch with the regimental staff, was at times subordinated to the commander of Smolensk; all orders which I received from that last-named command came via General Oberhäuser, who either approved or refused to allow the regiment to be employed for a particular purpose.
In other words, I received my orders exclusively from General Oberhäuser.