A wireless sensor network is comprised of a large number of battery-limited sensor nodes communicating with unreliable radio links. The nodes are deployed in an ad hoc fashion and a reverse multicast tree is formed in the target domain. The sink node disseminates a query and collects responses from the sensors over pre-established links. Survivability in wireless sensor networks reflects the ability of the network to continue to detect events in the case of individual node failures. We present a sender initiated path switching algorithm that enables the immediate sender to change the packet's route dynamically when its parent on the reverse path is down. The overall effect of path switching on the survivability is analyzed as a measure of reliable event delivery. Using independent battery capacities, an analytical model of a multihop network is derived. The model is used to predict the maximum network lifetime in terms of total transmitted messages; which is in turn used to verify the correctness of our simulations. The results have revealed that dynamic path switching has a better performance than static multipath routing and salvaging schemes. It has also been shown that the proposed approach enhances reliability up to 30% in some topologies.
Abstract-Multimedia applications in wireless sensor networks (WMSN) have stringent quality of service (QoS) requirements. In this paper, we study image quality distortions due to packet losses in multi hop WMSN. An experimental simulation and real testbed environment has been setup to estimate the quality of the test images over 30,000 transmissions. Two scenarios are considered: in the first scenario, images are watermarked with their replicas at the source node and an error concealment (EC) algorithm is employed at the sink. In the second scenario, raw images are transmitted without any encoding. The empirical results have revealed that there is a strong correlation between Peak-SignalTo-Noise-Ratio (PSNR) values of the distorted images and packet loss rate of the transmission route (PER). Moreover, the relationship is linear when EC technique is used with an achievement over 25dB PSNR for PER less than 0.6. This correlation is useful when designing QoS based transport schemes.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.