An opportunistic routing for real-time data in Wireless Sensor Networks

In this paper, we propose an opportunistic real-time data dissemination protocol in order to solve the transmission failure problem in error-prone WSNs. Retransmission is wellknown for recovery of transmission failure, however, this may cause the severe time delay possibly to violate the real-time requirement. To solve the problem, our protocol exploits both broadcasting nature and temporal opportunity concept. In a radio-range of a sensor node, there may be multiple neighbor nodes to satisfy the real-time requirement. By broadcasting property, all neighbors can receive a data from a node, and only each satisfying neighbor decides its relay toward the destination by using temporal selection function. The temporal function is related to the tolerable time period to be able to satisfy the realtime requirement. By giving the priority to the node with smaller tolerable time, we have more opportunities to forward toward the destination. That is, even if a node with a long tolerable time waits for the longer period of time, it still has a chance to forward with the real-time requirement. In summary, the proposed protocol attains the high reliability and real-time requirement by removing data retransmission and multiple opportunities with temporal consideration. Simulation results show that the proposed protocol is superior to the existing real-time protocols in terms of real-time data dissemination and energy consumption.