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ABSTRACT Data aggregation protocols are essential for wireless sensor networks to prolong network lifetime by reducing energy consumption of sensor nodes. For mission-critical wireless sensor networks, however, not only the energy consumption of sensor nodes but also the correctness of the data aggregation results is critical. As wireless sensor networks are usually deployed in harsh and hostile environments, malfunctioning and/or compromised sensor nodes negatively affect the correctness of the data aggregation results. This paper presents a fault-tolerant data aggregation scheme that eliminates the false data sent by malfunctioning and/or compromised sensor nodes. To conserve energy while eliminating false data, an in-network outlier detection technique that is based on locality sensitive hashing scheme is used. The simulation results show that the proposed scheme is able to reduce the number of false data transmissions, thereby increasing the data aggregation accuracy. Moreover, it is also observed that the proposed scheme reduces the overall data transmission in the network. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

This paper presents an energy efficient medium access control (MAC) protocol for delay-sensitive data transmission over wireless sensor network. In general, energy consumption and delay depend on channel monitoring interval (CMI) and data sensing period at each sensor node. Based on this fact, we propose a new preamble structure to effectively advertise CMI and avoid the overhearing problem. In order to pursue an effective tradeoff between energy consumption and delay, we also develop a CMI determining algorithm that searches for a sub-optimal solution with a low computational complexity in a distributive way. Finally, experimental results are provided to compare the proposed MAC protocol with existing sensor MAC protocols. Copyright © 2010 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

ICWASNs are a kind of wireless networks where, due to mobility of nodes and lack of connectivity, there may be frequent disconnections among the nodes. Hence, the routing path from the source to destination will not be available always. It is proven that, in these networks, messages are replicated multiple times in order to withstand the maximum delay and to achieve high throughput. But these multiple replication-based protocols result in an increase in network overhead and high resource consumption because of uncontrolled replication. Previous works in ICWASNs assume that networks will always have multiple partitions, and each message will be routed using store and forward mechanism. If source and destination are connected, then it is not needed to replicate multiple copies and waste the resources. We introduce a new simple scheme which applies single-copy routing if destination is available; else it switches to store and forward routing. The proposed system tries to reduce the average number of message replications while increasing the throughput. [ABSTRACT FROM AUTHOR]

Energy savings have always been the primary concern in wireless sensor network protocols, however there are applications where latency and throughput are prioritized over energy efficiency and are so significant that the application would not be able to satisfy its requirements without them. The communication unit and the antenna operation consume most of the battery-powered energy of the node. Thus, the access to the medium must be controlled in a very strict manner in order to avoid collisions which result in lost transmissions and have a dramatic impact on the lifetime of the network. Although existing duty cycle MAC protocols are power efficient, they introduce significant end-to-end delivery latency and provide poor throughput. In this paper, we propose SN-MAC, a CDMA-based power controlled medium access protocol that uses both transmitter-based and receiver-based CDMA inside a formed cluster, and uses a TDMA schedule to make the cluster heads communicate with the base station. Our algorithm targets latency and throughput needs in addition to its ability to increase the overall network lifetime. We provide a head-to-head comparison with other protocols through extensive simulations focusing on the performance in terms of latency, throughput, and energy consumption. [ABSTRACT FROM AUTHOR]

In designing a real-time MAC protocol for wireless sensor networks, it is desirable to shorten the data acquisition cycle time to satisfy more applications with a tighter time constraint in data collection. To achieve this, one often tries to improve throughput by employing a slot reuse technique. Meanwhile, the slotted sense multiple access protocol that uses a sharable slot was proven to be advantageous for timely and reliable data delivery. However, since the nodes at lower tree levels process more packets or bigger packets with data aggregation, they need a bigger sharable slot. Thus, it is not easy to employ a slot reuse technique due to the size variation of sharable slots. To tackle this problem, we try to reduce the size of an aggregated packet by limiting the number of packets for aggregation using two channels. If every node is allowed to send a single packet during data acquisition cycle time, an equal-sized sharable slot can be allocated to every tree level. It is shown that the proposed approach can reduce data acquisition cycle time significantly while maintaining good reliability in data transmission compared with slotted sense multiple access and also reduce energy consumption greatly compared with another multi-channel MAC protocol. [ABSTRACT FROM AUTHOR]