Cross-Layered Approach for (m, k)-Firm Stream in Wireless Sensor Networks

摘要

As most sensor nodes are deployed to detect and transmit interesting events or phenomena around them, the real-time delivery of sensed information within a predetermined deadline becomes one of the biggest challenges in wireless sensor networks. Even though some of the recent research works have been published in specific field, they are designed to cover general purpose applications. Therefore, most of applications cannot be supported by existing schemes especially when the requirement is application-specific real-time. In order to solve this problem, we model the target application as a specific traffic, (m, k)-firm stream, which is known as hard real-time requirement, and then propose a scheme to guarantee real-time delivery. To develop these, we introduce a cross-layer design to bring collaboration between layers under the basic principle that real-time delivery will hardly achieve by independent scheme in each layer. Thus, the requirements of application are passed to lower layers and used to adjust transmission power, prioritize packets, and find the adequate path in order to meet (m, k)-firm constraints for any stream dynamically. Finally, simulation results reveal that low failure probability for real-time requirements on (m, k)-firm stream is achieved by the proposed scheme.