In this paper we present a signal processing methodology for sharing symmetric keys in personal area networks. Symmetric encryption and decryption are commonly used because of limitations in computing power and energy consumption. However, key sharing still imposes challenges regarding usability, computational complexity of algebraic key exchange algorithms, and security. Our approach is that keys are generated locally on devices by shaking them, and that the keys are equal if and only if the devices are shaken together. Based on practical assessments, we show that the key generation algorithm is able to generate keys from acceleration data with an average entropy of 13bit/key in 70% of the cases.

In wireless sensor networks, power consumption is one of the key design issues because a large number of sensor nodes are powered by cheap batteries. Switching the RF transceiver, which is one of the biggest power consumers in a sensor node, to low-power sleep mode as much as possible has been proven to be a very efficient way to save power with a factor of tens or even hundreds. So far, several schemes have been proposed to reduce the duty cycle of the RF transceiver by MAC layer scheduling. Among them, the wake-up-frame scheme and the WiseMAC are two very efficient protocols based on the so-called preamble sampling technology. This paper proposes combining these two schemes to obtain a further optimized low-power MAC protocol, called SyncWUF, for low-traffic wireless sensor network. Analytical and simulation results prove that our proposal achieves significant battery lifetime gain in different application cases without negatively affecting other important system parameters such as channel capacity and latency

In wireless sensor networks and wireless personal area networks, power consumption is one of the most important design criteria for each small device. One of the biggest power consumers in such a device, the RF transceiver, should normally always be kept powered on for possible incoming packets; this is very power inefficient. The preamble sampling scheme was proposed to enable a receiver to sample the channel only periodically with a very low duty cycle by sending a long wake-up-preamble before the data frame; this dramatically reduces the power consumption of the receiver. The paper proposes to use a wake-up-frame instead of a wake-up-preamble to optimize further the preamble sampling scheme, achieving an additional battery lifetime gain in the order of tens to hundreds percent in different topologies and traffic loads.

We present a system architecture called Sindrion which allows us to create a cheap, energy-efficient, wireless control network to integrate small embedded sensors and actuators into one of the most established middleware platforms for distributed semantic services, namely universal plug and play (UPnP). To meet rigid constraints regarding cost and power consumption, complex data processing is sourced out from the sensor or actuator nodes to dedicated computing terminals, which establish a proxy in the UPnP network.

We present-a low-complexity soft detection and soft decoding magnetic disk drive read channel with a modified soft-output signal space detector (S/sup 3/D) which uses 3D-110 equalization and an error/erasure decoding Reed Solomon (RS) code. The detector determines max-log reliability information for intersymbol interference (ISI) channels with stationary white and colored noise. It can be implemented with only little additional hardware compared to the ordinary signal space detector. The erasures of the RS code are determined by the soft information and by an additional inner error detecting code (EDC) which is matched to the error patterns of the S/sup 3/D. The proposed system permits an improvement of the decoding performance in practical hard disk applications.