In the US, that regulation is close to becoming a reality as we wait for the Federal Aviation Administration (FAA) to publish its Notice of Proposed Rulemaking (NPRM) later this year. A fully automated and reliable system needs to be in place and available to ATC in case of emergency. In the case of general aviation (GA), there is already a similar technology called ADS-B (Automatic Dependent Surveillance and Broadcast) which constantly transmits location, direction of flight, altitude, speed