Jesús E. Villadangos

Fuzzy location and tracking on wireless networks

This paper describes user location and tracking on indoor scenarios through a wireless network. We propose a fuzzy location algorithm, using fuzzy inference systems, in order to deal with imprecise location based on radio-frequency trilateration estimations, providing high location rates near to 90. This indoor positioning approach is based on the pattern recognition of IEEE 802.11 (WiFi) signal strength measurements using fuzzy logic to deal with the vagueness and uncertainty of the trilateration based on signal strength. User location and tracking are considered in order to provide complete intelligent location based services. Fuzzy location techniques allow increasing location ratios even when the user trilateration can not be as precise as desired. Fuzzy tracking is performed by means of a fuzzy automaton.

An easy to deploy street light control system based on wireless communication and LED technology.

This paper presents an intelligent streetlight management system based on LED lamps, designed to facilitate its deployment in existing facilities. The proposed approach, which is based on wireless communication technologies, will minimize the cost of investment of traditional wired systems, which always need civil engineering for burying of cable underground and consequently are more expensive than if the connection of the different nodes is made over the air. The deployed solution will be aware of their surroundings environmental conditions, a fact that will be approached for the system intelligence in order to learn, and later, apply dynamic rules. The knowledge of real time illumination needs, in terms of instant use of the street in which it is installed, will also feed our system, with the objective of providing tangible solutions to reduce energy consumption according to the contextual needs, an exact calculation of energy consumption and reliable mechanisms for preventive maintenance of facilities.

Pattern Matching Techniques to Identify Syntactic Variations of Tags in Folksonomies

Folksonomies offer an easy method to organize information in the current Web. This fact and their collaborative features have derived in an extensive involvement in many Social Web projects. However they present important drawbacks regarding their limited exploring and searching capabilities, in contrast with other methods as taxonomies, thesauruses and ontologies. One of these drawbacks is an effect of its flexibility for tagging, producing frequently multiple syntactic variations of a same tag. In this paper we study the application of two classical pattern matching techniques, Levenshtein distance for the imperfect string matching and Hamming distance for the perfect string matching, to identify syntactic variations of tags.

A distributed data gathering algorithm for wireless sensor networks with uniform architecture

Wireless sensor networks (WSNs) are commonly used for continuously monitoring applications. Data gathering and in-network processing are techniques to efficiently gather the information from sensor nodes. Usually, these techniques have been analyzed taking into account a global knowledge of the system in order to select the best path to gather the information or to establish a routing function. In this paper we propose a novel distributed data gathering algorithm for wireless networks and evaluate the effect of having a different number of cluster heads transmitting to the base station. We focus the attention on uniformly distributed nodes in a given area to evaluate the effects on the energy consumption. Our proposal distributes uniformly the energy consumption between the complete set of sensors in the system resulting in a similar longevity for all sensors in the system

Data Aggregation in Wireless Sensor Networks

Serial data aggregation ensures minimal energy consumption since only one sensor initiates the algorithm and each sensor communicates only once with its successor. But it is difficult in a real scenario (essentially distributed) to synchronize all sensors to collaborate. In this paper we propose a linear distributed algorithm to aggregate data and we simulate it for different scenarios using the ns2 network simulator. We conclude that the proposed algorithm consume energy in a uniform way.

Analysis of Wireless Sensor Network Topology and Estimation of Optimal Network Deployment by Deterministic Radio Channel Characterization

One of the main challenges in the implementation and design of context-aware scenarios is the adequate deployment strategy for Wireless Sensor Networks (WSNs), mainly due to the strong dependence of the radiofrequency physical layer with the surrounding media, which can lead to non-optimal network designs. In this work, radioplanning analysis for WSN deployment is proposed by employing a deterministic 3D ray launching technique in order to provide insight into complex wireless channel behavior in context-aware indoor scenarios. The proposed radioplanning procedure is validated with a testbed implemented with a Mobile Ad Hoc Network WSN following a chain configuration, enabling the analysis and assessment of a rich variety of parameters, such as received signal level, signal quality and estimation of power consumption. The adoption of deterministic radio channel techniques allows the design and further deployment of WSNs in heterogeneous wireless scenarios with optimized behavior in terms of coverage, capacity, quality of service and energy consumption.

Design and Implementation of Context Aware Applications With Wireless Sensor Network Support in Urban Train Transportation Environments

Transportation system is experiencing steady growth, with the aim of providing more efficient, reliable, and comfortable services, in the framework of intelligent transportation systems. Moreover, context aware environments are one of the main drivers in the achievement of smart cities and smart regions. In this paper, wireless sensor networks (WSNs) embedded in urban transportation systems will be analyzed in terms of impact on wireless channel behavior and system performance. An in-house developed 3-D ray launching tool, with the inclusion of in-house human body model as well as with the study of interference levels is employed. Wireless channel estimations indicate an initial infrastructure node density in the order of 1node/150m2 to 1node/500m2 as a function of the employed transceivers. A practical solution has been implemented, combining an Android-based application and a system level architecture over the WSN for urban train transportation environmental monitoring, providing interaction between users and the environment, with the aid of a combined WSN/WLAN platform as well as an implemented software architecture, scalable in terms of user density and future needs.

Efficient leader election in complete networks

Leader election is a fundamental problem in distributed computing and it has been studied assuming various computation models and network topologies. This paper analyzes the algorithms for leader election in complete networks using asynchronous communication channels. We present a novel algorithm that reduces the information necessary to select a leader compared with other leader election algorithms for complete networks. In this paper, the algorithm works without sense of direction. And, it does not require to know the number of nodes in the system. Our proposal requires O(n) messages and O(n) time, where n is the number of nodes in the system, to elect a leader.

Ubiquitous Connected Train Based on Train-to-Ground and Intra-Wagon Communications Capable of Providing on Trip Customized Digital Services for Passengers

During the last years, the application of different wireless technologies has been explored in order to enable Internet connectivity from vehicles. In addition, the widespread adoption of smartphones by citizens represents a great opportunity to integrate such nomadic devices inside vehicles in order to provide new and personalized on trip services for passengers. In this paper, a proposal of communication architecture to provide the ubiquitous connectivity needed to enhance the smart train concept is presented and preliminarily tested. It combines an intra-wagon communication system based on nomadic devices connected through a Bluetooth Piconet Network with a highly innovative train-to-ground communication system. In order to validate this communication solution, several tests and simulations have been performed and their results are described in this paper.

Ontology Based Road Traffic Management

Every time an abnormal situation happens on the road, danger situations are found and they need the skills of the drivers in order to cope with them. In this paper, we propose to integrate an ontology inside each vehicle to provide them with reasoning capabilities and avoid the use of a central decision point. Our system benefits traffic management in emergency situations with immediate decisions where each vehicle is a decision point, reacts considering its neighbouring vehicles, and collaborates with them to reach consensus in real time.