  In this study, we propose a novel positioning and searching system for
emergency location services, namely the hyper-enhanced local positioning system
(HELPS), which is applicable to all mobile phone users, including legacy
feature phone users. In the case of an emergency, rescuers are dispatched with
portable signal measurement equipment around the estimated location of the
emergency caller. Each signal measurement device measures the uplink signal
from the mobile phone of the caller. After calculating the rough location of
the caller's mobile phone based on these measurements, rescuers can efficiently
search for the caller using the received uplink signal strength. Thus, the
positioning accuracy in a conventional sense is not a limitation for rescuers
in finding the caller. HELPS is not a traditional positioning system but rather
a system with humans in the loop designed to reduce search time in emergencies.
HELPS can provide emergency location information even in environments where the
GPS or Wi-Fi is not functional. Furthermore, for HELPS operation, no hardware
changes or software installations are required on the caller's mobile phone.
