Patent ID: 8442485

Claim:
A method comprising: recording a first timestamp from a packet when a packet data session reflects user activity that is initiated by a user on a mobile node, the recording including causing a first timestamp to be recorded based on certain user activity and distinguishing control packets such that a timestamp is not recorded for at least some types of control packets; monitoring packets reflecting user activity sent or received by the mobile node after the first timestamp; recording a second timestamp based on an envelope of a packet sent or received by the mobile node; repeatedly updating the second timestamp based on an envelope of a subsequent packet reflecting subsequent user activity; determining a period of inactivity; triggering a reporting threshold based on time and/or volume responsive to the determination of a period of inactivity; and reporting to a server a user data session duration based on a time from the first timestamp to the second timestamp, such that the time does not include time after the second timestamp indicating a subsequent packet reflecting subsequent user activity; wherein a mobile user can be charged only for data usage consisting of packets reflecting user activity and not for at least some types of control packets.