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Wireless Sensor Networks (WSNs) consist of small nodes with sensing, computation, and wireless communication capabilities. Wireless Sensor Network (WSN) is a promising data mining solution for precision agriculture. Instrumented with wireless sensors, it will become available to monitor the plants for real time, such as air temperature, soil water content, and nutrition stress. This real time information...
We have investigated a wearable video system to capture our experiences by a wearable camera, microphone and some sensors including GPS receiver, etc. GPS receiver was used to record the user's tracks and identify the location of user's experiences by latitude and longitude coordinates. GPS receiver can also extract time, speed and direction that are benefit contexts for wearable video navigation...
In this paper, we propose a distributed algorithm to calculate a subgraph of a given wireless sensor network (WSN) connecting a set of sources and a set of sinks such that: 1) the length of a path connecting from a source to a sink in the subgraph does not exceed the distance from the source to the farthest sink, and 2) the number of links contained in the subgraph is minimized. The proposed algorithm...
In cognitive radio systems, secondary users can be coordinated to perform cooperative spectrum sensing to overcome the hidden terminal problem. However, when the number of cooperative users tends to be very large, too many cooperative users will make the whole sensing time intolerantly long and huge consumption of system resource. In this paper, we studied optimal number of secondary users in cooperative...
Jamming attacks are considered one of the most devastating attacks as they are difficult to prevent and sometimes hard to detect. In this paper we consider the impact of the placement and range of limited-range jammers on ad hoc networks. Limited range jammers are more difficult to detect as they use transmission powers similar to that of regular nodes (or perhaps even smaller transmit powers). The...
There is a growing need for enabling reprogramming in a working sensor network. We prefer to meet the requirements remotely instead of collecting all deployed sensors. Identifying the version difference of data items, having the same key, could significantly reduce the communication overhead, because only those out-of-date items should be updated at each sensor. Previous protocols need to exchange...
We propose a novel parallel mixed-signal compressive spectrum sensing architecture for cognitive radios (CRs) with a detailed study of the signal modeling. The mixed-signal compressive sensing is realized with a parallel segmented compressive sensing (PSCS) architecture, which not only can filter out all the harmonic spurs that leak from the local random generator, but also provides a tradeoff between...
In this paper a communication system operating over a Gilbert-Elliot channel is studied. The goal of the transmitter is to maximize the number of successfully transmitted bits. This is achieved by choosing among three possible actions: (i) betting aggressively by using a weak code that allows the transmission of a high number of bits but provides no protection against a bad channel, (ii) betting conservatively...
Spectrum sensing is an important component of cognitive radio technology. Cooperative spectrum sensing is regarded as the most promising method to improve the reliability of spectrum sensing. However, such cooperation also introduces overhead traffic of control signaling and result transmission which consumes more power in battery operated mobile terminals. In this paper, an RLECSS (run-length encoding...
Spectrum sensing is the key enabling technology for cognitive radio networks. The main objective of the spectrum sensing is to provide more spectrum access opportunities to cognitive radio (CR) users without interfering with the licensed users. In this paper, we propose a half-voting based twice-cooperative spectrum sensing scheme. Simulation results show that the proposed sensing method can achieve...
Among variant kinds of spectrum sensing strategies in cognitive radio (CR) broadly studied before, cooperative sensing is the most popular one to detect the primary user accurately. This paper proposes a new cooperative spectrum sensing algorithm in which double threshold energy detection will be employed at local decision and different fusion rules will be used at the fusion center. Theoretic analysis...
Cognitive radio is observed as a new approach, which could be cope with the spectral limitations. This approach is designed to detect whether a particular segment of the radio spectrum is currently in use and to jump into the temporarily unused spectrum rapidly without interfering with the transmissions of other users. CR is the promising radio technology which aims to detect and utilize the temporally...
This paper discusses the problem of joint location and orientation estimation of a receiver using only angle of arrival (AOA) information. Conventional formulations of the problem consist of a number of nonlinear equations where the number of unknowns exceeds the number of equations. However, formulations presented in this paper simplifies the problem in a way that leads of efficient solutions. Two...
WirelessHART is an emerging wireless communication standard that is targeted at the real-time process control industry.An example application of wireless communication in an industrial process control plant is the location of field engineers. The capability to locate personnel is a safety critical issue in process control plants because of high risks posed by toxic chemicals and other hazards. This...
Spectrum sensing is a critical phase in building a cognitive radio network. However, when the number of cognitive user is very large, the bandwidth for reporting cognitive users' sensing results will be insufficient. In this paper, we propose a new cooperative spectrum sensing algorithm to alleviate the bandwidth problem of reporting channel. Compared with conventional method, only the cognitive users...
This work proposes a novel algorithm for energy-efficient and reliable spectrum sensing in a cognitive network. The algorithm relies on cooperation between secondary devices, that organize themselves in clusters defined according to both sensing reliability and energy efficiency. The proposed algorithm is compared by means of computer simulations with a simpler, non cluster-based cooperative sensing...
Monitoring underwater environments is critical for future near-shore exploration and port security. The effectiveness of underwater acoustic sensor systems is affected by the water environment, as sharp gradients in salinity and temperature cause sound to refract and reflect. Sound transmission can be impaired in estuaries where the salinity of the water is highly variable in space, and tidal action...
This paper develops the coherent generalized likelihood ratio test (GLRT) and the MVDR statistic for multistatic radar systems, conditioned on estimation of certain parameters that render the system coherent. Analytical and computer simulation results are presented to show substantially enhanced detection and geolocation of moving targets in clutter.
This paper describes a design of a data logger based system dedicated to vehicle trajectory monitoring. The system evaluation is based on prototyping an embedded application. The adopted architecture allows tests and applications and results are obtained with a set of constraints. In this multisensors architecture, a GPS receiver is used for the absolute localization. In order to integrate the GPS...
Despite its inherent inaccuracy, RSSI has been used as the standard tool for distance measurements in the majority of range-based localization protocols available in the literature. In this paper, we propose a technique to enhance the accuracy of RSSI-based distance measurements using calibration. Our technique depends on the existence of location-aware anchor nodes that are distributed across the...
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