The technology is available and has been in use by the military for some time, as the background material in this Reuters article on AirAsia QZ8501 makes clear:
AirAsia crash makes case for ejectable black boxes | Reuters
In theory, it was discussed at the ICAO High Level Safety Conference in February last year
HLSC
but I can't quickly find anything in the publicly available documentation. Enhanced tracking was discussed, as these reports make clear - see page 60 of the pdf
http://www.icao.int/Meetings/HLSC201...s/10046_en.pdf
and
Air Transport News
and
ASN News » ICAO member states recommend new flight tracking performance standard