ANSAR: Ad hoc Network State Aware Routing Protocol Jie Xiang [email protected] Simula Resarch Laboratory Outline • Issues in Ad hoc Networks • Related Works • Description of ANSAR • Simulation • Conclusion 2 Issues in Ad hoc networks • Limited power available at the nodes. • The topology of Ad hoc Networks can change arbitrarily. • The energy constrained network will experience Ideal state, Congested State, and Energy Critical State 3 Related Works metrics example drawbacks Shortest hop DSR, Easily concentrate traffic metric AODV, on centrally located DSDV nodes Load Aware DLAR May divert load to low Metric energy capacity nodes. Energy Aware MTPR, Tend to concentrate Metric MBCR, traffic load on nodes with MMBCR high battery capacity. 4 Problem Statement • Problem – Limitation of nodes’ battery capacity – Network state changed from ideal to critical – Dynamic topologies • Objective – Adaptive to the network state – Optimize the network life time, minimize the energy consumed. 5 Assumptions • Energy consumed due to computation related activities is negligible compared to communication related activities. • All data packets are of the same size. • The energy consumed per unit transmission, reception and overhearing of a packet are constant, denoted by e , e , e respectively ix ir io for node i. 6 Notations • RBC: Remaining Battery Capacity • ED: Energy Drained • EDR: Energy Drain Rate • NL: Node Lifetime • PL: Path Lifetime 7 ANSAR routing metric deduction The Energy Drained of node i at time t The Energy consumed: calculated by the node’s Load 8 ANSAR routing metric deduction Energy Drain Rate 9 ANSAR routing metric deduction Node Life Path Life The best path The reserved path 10