A simple load-balancing approach in secure ad hoc networks

Most ad-hoc routing protocols such as AODV and DSR do not try to search for new routes if the network topology does not change. Hence, with low node mobility, traffic may be concentrated on several nodes, which results in long end-to-end delay due to congestion at the nodes. Furthermore, since some specific nodes are continuously used for long duration, their battery power may be rapidly exhausted. Expiration of nodes causes connections traversing the nodes to be disrupted and makes many routing requests be generated at the same time. Therefore, we propose a load balancing approach called Simple Load-balancing Approach (SLA), which resolves the traffic concentration problem by allowing each node to drop RREQ or to give up packet forwarding depending on its own traffic load. Meanwhile, mobile nodes may deliberately give up forwarding packets to save their own energy. To make nodes volunteer in packet forwarding we also suggest a payment scheme called Protocol-Independent Fairness Algorithm (PIFA) for packet forwarding. To evaluate the performance of SLA we compare two cases where AODV employs SLA or not. Simulation results show that SLA can distribute traffic load well and improve performance of entire ad-hoc networks.