An Efficient Tree-Based Geocast Routing Algorithm for Connecting Heterogeneous Networks

This paper describes a new tree-based routing method which can be used to connect heterogeneous networks. In the proposed method, a source node located in one network sends packets to a group of nodes in another network. In our scenario, a source node normally belongs to a mobile ad hoc network, while a group of nodes consists of sensor nodes in the specified geographical region. The source node sends a packet to destination nodes in order to aggregate sensor data. Our protocol attains energy efficiency and accuracy by incorporating a metric for constructing the tree according to routes. The metric is calculated using parameters such as power and neighborhood connectivity. Before constructing a tree, hello messages are sent, depending on local mobility, for updating the list of neighbors. After constructing the tree, the link lifetime is evaluated periodically in order to maintain the freshness of a link along the route. In order to verify the performance of the proposed scheme, we conducted a set of computer simulations using the OPNET modeler. We measured the performance of the system in terms of delay, packet loss and accuracy of packet delivery. Results are compared to those of a conventional method. The results show that the proposed method improves efficiency by as much as 20% compared with that of a conventional method.