An Enhanced Backbone-Assisted Reliable Framework for Wireless Sensor Networks

An extremely reliable source to sink communication is required for most of the contemporary WSN applications especially pertaining to military, healthcare and disaster-recovery. However, due to their intrinsic energy, bandwidth and computational constraints, Wireless Sensor Networks (WSNs) encounter several challenges in reliable source to sink communication. In this paper, we present a novel reliable topology that uses reliable hotlines between sensor gateways to boost the reliability of end-to-end transmissions. This reliable and efficient routing alternative reduces the number of average hops from source to the sink. We prove, with the help of analytical evaluation, that communication using hotlines is considerably more reliable than traditional WSN routing. We use reliability theory to analyze the cost and benefit of adding gateway nodes to a backbone-assisted WSN. However, in hotline assisted routing some scenarios where source and the sink are just a couple of hops away might bring more latency, therefore, we present a Signature Based Routing (SBR) scheme. SBR enables the gateways to make intelligent routing decisions, based upon the derived signature, hence providing lesser end-to-end delay between source to the sink communication. Finally, we evaluate our proposed hotline based topology with the help of a simulation tool and show that the proposed topology provides manifold increase in end-to-end reliability

A1: An energy efficient topology control algorithm for connected area coverage in wireless sensor networks

Energy consumption in Wireless Sensor Networks(WSN’s) is of paramount importance, which is demonstrated by the large number of algorithms, techniques, and protocols that have been developed to save energy, and thereby extend the lifetime of the network. However, in the context of WSN’s routing and dissemination, Connected Dominating Set (CDS) principle has emerged as the most popular method for energy-efficient topology control (TC) in WSN’s. In a CDS-based topology control technique, a virtual backbone is formed which allows communication between any arbitrary pair of nodes in the network. In this paper, we present a CDS based topology control protocol – A1 – which forms an energy efficient virtual backbone. In our simulations, we compare the performance of A1 with three prominent CDS-based protocols namely Energy-efficient CDS (EECDS), CDS Rule K and A3. The results demonstrate that A1 performs consistently better in terms of message overhead and other selected metrics. Moreover, the A1 protocol not only achieves better connectivity under topology maintenance but also provides better sensing coverage when compared with the other protocols

Using Session-Keystroke Mutual Information to Detect Self-Propagating Malicious Codes

Abstract — In this paper, we propose an endpoint-based joint network-host anomaly detection technique to detect selfpropagating malicious codes. Our proposed technique is based on the observation that on any endpoint there exists very high correlation between benign network sessions and the keystrokes that trigger these sessions. Specifically, users generally use a few keystrokes to trigger most of the benign network sessions. On the other hand, malicious sessions originating from a compromised endpoint will not have the session-keystroke correlation. We leverage this observation in a novel information-theoretic framework that characterizes the session-keystroke correlation in terms of their mutual information. Changes in session-keystroke mutual information are used to detect malicious codes in an automated and real-time fashion. To evaluate the proposed anomaly detector, we use actual traffic and keystroke data collected on benign and infected endpoints. We show that the proposed anomaly detector provides almost 100 % detection with negligible false-alarm rates and significantly surpasses the accuracy of existing techniques. I

On the Impact of Ignoring Markovian Channel Memory on the Analysis of Wireless Systems

Abstract – Recent wireless measurement studies have revealed the presence of high-order memory in wireless bit-error channels. However, most wireless studies continue to employ the memory-less or 1 st order Gilbert bit-error channels to design, analyze and verify wireless protocols and systems. The inaccuracies incurred by ignoring high-order channel memory are largely unexplored. This paper quantifies inaccuracies incurred by ignoring bit-level wireless channel memory in the context of two simple and commonly-used protocol metrics: (i) packet goodput of an abstract unreliable protocol and (ii) number of retransmissions per packet for an abstract reliable protocol. We analytically derive expected values of these metrics in terms of the parameters of four models with varying levels of memory. We then train the models using actual 802.11b bit-error traces and use the analytical expressions to estimate the metrics. Comparison of the model-based estimates with actual values of the metrics derived from the traces shows that the memory-less and 1 st order models incur significant inaccuracies. The remaining two models that capture high-order memory are very accurate in their estimates of the crucial goodput and retransmission metrics. I