Nodes’ Credit based Directed Diffusion for wireless sensor networks* Farnaz Dargahi, Amir Masoud Rahmani, Sam Jabehdari Azad University science and research branch, Tehran, Iran, E-mail:farnazdargahi@gmail.com, rahmani@sr.iau.ac.ir, Azad University north Tehran branch E-mail:sjabehdari@gmail.com Abstract. For data gathering in wireless sensor networks, sensors extract useful information from environment; this information has to be routed through several intermediate nodes to reach the destination. How information can effectively disseminate to the destination is one of the most important tasks in sensor networks. Problem arises when intermediate nodes fail to forward incoming packets. Due to limited power and slow processor in each node, algorithms of sensor networks must be designed carefully. Directed Diffusion (DD) is a typical data-centric algorithm which has been used to provide efficient data transmission. We enhance this algorithm based on nodes' credit by using five factors. Simulation results show that our proposed algorithm is more energy efficient and reliable than DD and has the ability of traffic load distribution. Keywords: Directed Diffusion, Data gathering, Nodes’ Credit, Sensor network. 1 Introduction A sensor network is a group of wireless nodes randomly distributed in a region. In most data gathering applications, information produced by one or more sources usually has to be routed through several intermediate nodes; these wireless nodes have the ability of packet forwarding, i.e. relaying incoming packets to one of its neighbor nodes. Problem arises when intermediate nodes fail to forward incoming packets. Sensor nodes have many failure modes. Each failure decreases the performance of data gathering procedure. Our approach is designed by considering that nodes maybe not available during the dissemination procedure. Directed Diffusion [1] is a routing mechanism for data gathering in which data consumer (sink)search for the data sources by sending interest packets and * This work was supported by Iran Telecommunication Research Center (ITRC). International Journal of Grid and Distributed Computing 39