A method and system allowing a mobile phone user to "opt in" to requests with
multiple
response options, to respond indicating that user wishes not to be tracked, or
to respond indicating some information about state, possibly in addition to PVT
information. The user has options besides allowing ping responses or turning off
GPS tracking. When a ping is received, user chooses whether or not to opt in to
the ping. The user may refuse to respond, to respond normally with or without PVT
or other information, or to respond saying only that the mobile phone is turned
on. GPS tracking continues to operate, so that upon return to normal responses,
no cold start of GPS tracking is involved. More intelligent, such as for example
rules-based, responses can be made to ping messages, in which GPS tracking interacts
with a user interface to determine how to respond flexibly to pings.
