A Lookahead Strategy for Movement-Based Location Update in Wireless Cellular Networks

We present a lookahead strategy for a movement-based location update that reduces the signalling traffic of the classical movement-based procedure. Our proposal is based on the fact that many trips of the mobile terminals follow routinary trajectories, for instance from home to the office or from the office to the shopping center. Based on a mobile terminal movement model that captures the mentioned behavior, the network predicts the mobile's location at cell level. If the mobile terminal visits an expected cell, the target cell Delta, before a certain movement threshold is reached, its movement counter is reset to zero. Otherwise the mobile terminal will trigger a location update message when the mentioned threshold is reached. With this strategy the mobile terminal has less contact with the network, so the uncertainty on its location increases. As a consequence, in order to keep the paging cost below reasonable bounds, a selective polling strategy is used. The net effect is a significant saving in the signalling traffic supported in the air interface.