Sorry, buy I don't see where the pdf link relates to GPR.
There could be "something there" with regard to the Plasma Antenna tech, however. It supposedly allowed high-speed data transmission at any frequency, thus providing security by ultilizing frequency levels that no other device could detect. So it went beyong "licensed" and "unlicensed" frequencies to unused frequencies only available via use of the Plasma (ionized gas) Antenna by sender and receiver.
SGE