A user selects a route between a starting point and a destination. A
mobile handset monitors the user's progress along the route by monitoring
the location and movement of the handset and, optionally, sensor data,
and by comparing this information to rules that define permitted or
prohibited locations or movements or threshold sensor values. The handset
uses one or more positioning systems, such as GPS, to ascertain its
location. A server provides the handset with information to correct
errors in the location information. If a rule fires, possibly indicating
that the user is in danger, the handset attempts to ascertain the user's
wellbeing, warns the user to return to the prescribed route and begins
sending the handset's location to a server, which displays the
information to a dispatcher who dispatches safety or security personnel
to the user's location. The handset and servers communicate via any
available wireless channel(s).