At sea, high winds and sea states can make locating people difficult, even with emergency beacons that provide GPS coordinates.

Today, both civilians and military personnel use emergency beacons that operate on the dedicated 406MHz frequency as part of the International Cospas-Sarsat satellite program dedicated to search and rescue.

Cospas-Sarsat is in the process of significantly upgrading their satellite system with Medium- altitude Earth Orbit Search and Rescue (MEOSAR) satellites.

Once operational, MEOSAR will make it much faster and easier for rescue crews to locate ships, aircraft and people in distress.

Another benefit of the MEOSAR technology will be a “return link” capability in the new generation of beacons to let the user know their distress message has been received and help is on the way.

Situational awareness is especially crucial in rescue situations, and the combination of MEOSAR satellites and wireless communications will dramatically improve both the speed and overall safety of such missions.

Read more here:
http://i-hls.com/2017/01/new-communications-technologies-will-help-search-rescue-crews/