Abstract: In this research, a Greedy Rumor Forwarding Routing (GRFR) protocol is proposed for Wireless Sensor/Actor Networks (WSANs) based on geographic information, which improves rumor routing protocol. The study explores the performance of GRFR including both the network lifetime and communication delay at two different system architectures based on the software simulation platform SensorSimulator, which is a discrete event simulation framework for the networks built over OMNeT++. Furthermore, it is deeply investigated how the sensor nodes within one hop from the sink affect the network lifetime.