A Personal Locator Beacon (PLB) is a device used by hikers, and people in remote locations to alert search and rescue personnel of a distress situation. The FCC authorized the use of Personal Locator Beacons on July 1, 2003. PLBs transmit distress signals on 406 MHz which is an internationally recognized distress frequency to the COSPAS-SARSAT satellite system. Each PLB is equipped with a unique identifying code which is a 15 digit alphanumeric code. This code is transmitted in the electronic burst to the satellites and is linked to a computer database maintained by NOAA.