Traditional utility-based data-gathering models consider the maximization of the gathered information and the minimization of energy consumption in WSNs with reliable channels. In this paper, we extend the model to include retransmissions caused by link failure to improve network utility. The challenge lies in balancing two competing factors: energy loss (and hence utility) through retransmissi...

∗ This work was supported by National Defense Pre-research Foundation of China. Abstract: Some works have been done in addressing real-time fault-tolerant scheduling algorithms. However, they all based on homogeneous distributed systems or multiprocessor systems, which have identical processors. This paper presents two fault-tolerant scheduling algorithms, RTFTNO and RTFTRC, for periodic real-t...

The efficiency of multi-hop communication is a function of the time required for data transfer, or throughput. A key determinant of throughput is the reliability of packet transmission, as measured by the packet reception rate. We follow a data-driven statistical approach to dynamically determine a link quality estimate (LQE), which provides a good predictor of packet reception rates. Our goal ...

This paper presents RECPE, a reliable collection protocol for aggregating data packets from all the sensor nodes to the sink in a large-scale WSN (wireless sensor network). Unlike some well-known reliable data collection protocols such as CTP (Collection Tree Protocol) that uses ETX (expected transmission count) as the routing metric, RECPE exploits ETF (expected transmission count over forward...

The growth of multimedia applications and wireless systems requires a new behavior of routing protocols for Wireless Mesh Networks (WMNs). It is necessary to provide not only the minimum requirements for Quality of Service (QoS), but also to assure the Quality of Experience (QoE) support for multimedia applications. In this context, the usage of only one link quality metric for routing differen...

In wireless networks, different links often have different signal power to noise power ratios (SNRs). SNR affects the reliability and throughput of a link. Current wireless systems adapt transmission power, modulation or coding to improve reliability and throughput, based on link SNR. However, all these systems transmit a modulated symbol for a fixed duration across all links. Theory and system...

Routing protocols that have been designed to run within a single administrative domain (IGPs) generally do so by assigning a metric to each link and then choosing, as the installed path between two nodes, the path for which the total distance (sum of the metric of each link along the path) is minimized. BGP, designed to provide routing over a large number of independent administrative domains (...

background: according to the measurements literature reliability of the test refers to the consistency of the test results and shows whether the obtained score is stable indication of the student’s performance in particular test reliability can be measured by different statistics formula. purpose: to determine the factors influenced the reliability of 392 mcq examinations. methods: the correlat...

Design diversity has long been used to protect redundant systems against common-mode failures. The conventional notion of diversity relies on “independent” generation of “different” implementations. This concept is qualitative and does not provide a basis to compare the reliabilities of two diverse systems. In this paper, for the first time, we present a metric to quantify diversity among sever...