A location management scheme based on pointers strategy in the roaming cluster for the ad-hoc networks

A major design issue in ad hoc networks is the problem of location management. In a "flat" network architecture, location management is handled by routing protocols; however, in large ad-hoc networks, the "flat" architecture is not efficient, so a roaming cluster (RC) scheme has been proposed to support location management in hierarchical ad-hoc networks. With the aim of reducing the cost of location updating, location registration is only updated when the mobile user exits the current roaming cluster. The cost and delay of paging a mobile user in such a hierarchical ad-hoc network architecture increases with the size of the roaming cluster. Based on the group character of the movement of mobile users in ad-hoc networks, we propose a forwarding pointers scheme to reduce the cost of paging mobile users. Unlike the RC scheme, we use a pointer to track the exact location of a mobile user during its movement in the roaming cluster. The design objective of using pointers is to reduce the paging cost and delay significantly with a moderate increase in the cost of location updating. We develop an analytical model that is applied to formulate the cost of location updating and of forwarding pointers maintenance. The performance of the forwarding scheme is evaluated through simulation to demonstrate its cost-effectiveness for large ad-hoc networks.