A real-time routing protocol for (m,k)-firm streams in wireless sensor networks

As a novel real-time application in wireless sensor networks (WSNs), multimedia transmission has posed a new challenge that both reliability and timeliness must be satisfied at the same time to support an acceptable quality of service (QoS). However, the inherent resource constraint of sensor nodes and instability of wireless communication make it not practical for existing routing mechanisms to meet the requirements of this QoS aware application. To address the problem, we propose an innovative protocol in this paper, for energy and QoS aware routing of (m,k)-firm based real-time applications over WSNs. The routing depends on optimal forwarding decision which takes into account of packet end-to-end deadline, node condition and remaining energy of next hop. A local status indicator (LSI), which was specially devised for (m,k)-firm stream, is used in the routing scheme for each node to monitor and evaluate its local condition. The proposed protocol has been well studied and verified through simulations. The results have proved the efficiency of the proposed routing protocol in terms of higher successful transmission ratio and smaller end-to-end delay.