Resetting forwarding pointers with delay propagation schemes in a distributed HLR environment

In this paper, we propose a new location tracking method for pointer forwar ding with distributed HLRs schemes to decrease the location tracking cost. Similar to tile distributed HLR schemes, the location information is replic ated on all HLRs in our scheme. However, unlike tile traditional distribute d HLR schemes, we propagate the most recent location changes from an HLR to reset the forwarding pointers in other HLRs, and thus reduce the cost of l ocation tracking for call deliveries. The signaling cost of location propag ation may be too costly to be practical. Therefore. we allow some inconsist ency to exist among the location data of HLRs and defer the propagation of location changes to reduce the propagation cost. Three delay propagation po licies are also proposed and analyzed using simulation. The performance res ult shows that the delay propagation policies reduce the propagation cost a nd tile propagation resetting process degrades tile location tracking cost. Our method preserves a low total cost for call deliveries. registrations a nd propagations in distributed HLRs.