Minimizing the wireless cost of tracking mobile users: an adaptive threshold scheme

A novel approach for user tracking, in which the tracking activity is adapted to both user activity is proposed. To carry out this approach, an Adaptive Threshold Scheme (STS) is introduced. In this scheme, the network determines for each cell a registration threshold level and announces it, as a broadcast message, to the users. A user computes its own registration priority and then transmits a registration message only if its priority exceeds the announced threshold level. Thus, whenever the local load of the cell is low, the users are requested to update their locations more often, while in loaded cells the registration activity is minimized.