Special issue: Sensor networks

Vol. 60, n° 7-8, July-August 2005
Content available on Springerlink

Guest editors
Otto Carlos Duarte, UFRJ, Brazil
Guy Pujolle, UPMC, Paris, France


Otto Carlos M. B. Duarte, Guy Pujolle

A bio-inspired field estimation scheme for wireless sensor networks

Daniel de O. CUNHA*, Rafael P. LAUFER*, Igor M. MORAES*, Marco D. D. BICUDO*, Pedro B. VELLOSO**, Otto Carlos M. B. DUARTE*

* Universidade Federal do Rio de Janeiro, Grupo de Teleinformática e Automação, PEE/COPPE – DEL/POLI – Av. Brig. Trompowski s/nº, Prédio do CT, Bloco H, Sala H-301, Ilha do Fundão, Rio de Janeiro, RJ, P.O. Box 68504, CEP 21945-970, Brasil.
** Laboratoire d’Informatique de Paris 6 (LIP6), Université Pierre et Marie Curie, 8, rue du Capitaine Scott, 75015 Paris, France.

Abstract This paper proposes and analyzes a bio-inspired field estimation scheme using wireless sensor networks. The proposed scheme exploits the temporal pattern of the sensed process to reduce the number of samples sent back to the sink by a sensor node and, as consequence, decrease the energy consumption in data transmission. The proposed scheme is orthogonal to the techniques that reduce the spatial density of collected samples deactivating nodes with similar measurements. Thus, the proposed scheme can be used along with these techniques. We present two variations of this scheme: a sample-bounded and an error-bounded. The sample-bounded limits the maximum number of samples sent back to the sink, while the error-bounded guarantees the observation of every event of interest. Results show that for very regular processes the scheme can reduce up to 90% the total amount of samples sent in the network and even for less regular processes the proposed scheme can reduce the total amount of samples sent from approximately 10 up to 20%, with small reconstruction errors.

Keywords Data collection, Measurement sensor, Temperature sensor, Radiocommunication, Data reduction, Biological model.

An autonomic-oriented architecture for wireless sensor networks


LIP 6, Université Pierre & Marie Curie (Paris 6) – 8 rue du Capitaine Scott, 75015 Paris, France

Abstract Autonomic communication is a new paradigm to enable network self-configuration, selforganization, self-healing, and autonomic behaviour. Emerging networks need this autonomic behaviour in order to ensure mainly quality of service, resilience and reliability of the network which is highly necessary for a long term service operation. Typical environments where such a deployment is extremely important come from wireless sensor networks. Indeed, sensor networks are strongly distributed and need for a self-organized and selfmanageable architecture to provide a reliable service support. To come up with these properties, this paper introduces a new autonomic-oriented architecture (AoA) for wireless sensor networks.

Keywords Data collection, Measurement sensor, Radiocommunication, Autonomous system, Selforganization, Distributed system, Network architecture.

Wireless sensor network self management: services, functions, models and case study

Linnyer B. RUIZ*, José Marcos NOGUEIRA**, Antonio A. F. LOUREIRO*

* Université Fédérale du Minas Gerais, Belo Horizonte, MG, Brésil
** Laboratoire d’Informatique de Paris 6 (LIP6), Université Pierre et Marie Curie, 8, rue du Capitaine Scott, 75015 Paris, France (en année sabbatique).

Abstract The wireless sensor networks (WSN) are a novel technology that has appeared after great advancements in the development of intelligent sensors, powerful microprocessors, and communication protocols, their basic components. This kind of network is composed by hundreds to thousands of elements and has the objective of data collecting, processing, and disseminating to a point of interest. The network elements, named sensors nodes, have small dimensions and resource restrictions, especially the energy, the processing, and the communication capacities. It is expected that the WSN are intelligent, autonomic, and context aware. To reach such an objective, they are supposed to perform the management of themselves, i.e., be selfmanaged. In this article, we propose a management solution for such a sort of network, based on the autonomic computing paradigm. In order to show that self-management can improve the productivity of the network and control the quality of the provided services, we present a case study of a heterogeneous and hierarchic WSN that collects and disseminates data continuously.

Keywords Data collection, Measurement sensor, Radiocommunication, Autonomous system, Management, Distributed system, Self-organization

A comparative study of distributed frequency assignment algorithms for wireless sensor networks


University of Waterloo School of Computer Science 200, University Avenue West Waterloo, Ontario, Canada N2L3G1

Abstract Wireless sensor networks are composed of energy constrained nodes embedding limited transmission, processing and sensing capabilities. The main research efforts in this area sought to prolong the network lifetime by reducing energy consumption of network operations. Data gathering mechanisms such as clustering have been shown to achieve significant energy savings. However, such benefits can be obtained only if neighboring clusters operate on different frequencies (channels). As the salient characteristics of wireless sensor networks favor a distributed approach, we analyze the performance of several distributed frequency assignment algorithms with a focus on energy consumption. In this context, we find that a heuristic may achieve better results than backtracking-based algorithms.

Keywords Data collection, Measurement sensor, Radiocommunication, Radio frequency management, Distributed algorithm, Energy consumption, Comparative study.

Multimedia communication in wireless sensor networks

Eren GÜRSES, Özgür B. AKAN

Department of Electrical and Electronics Engineering Middle East Technical University, Ankara, Turkey

Abstract The technological advances in Micro ElectroMechanical Systems (MEMS) and wireless communications have enabled the realization of wireless sensor networks (WSN) comprised of large number of low-cost, low-power, multifunctional sensor nodes. These tiny sensor nodes communicate in short distances and collaboratively work toward fulfilling the application specific objectives of WSN. However, realization of wide range of envisioned WSN applications necessitates effective communication protocols which can address the unique challenges posed by the WSN paradigm. Since many of these envisioned applications may also involve in collecting information in the form of multimedia such as audio, image, and video; additional challenges due to the unique requirements of multimedia delivery over WSN, e.g., diverse reliability requirements, time constraints, high bandwidth demands, must be addressed as well. Thus far, vast majority of the research efforts has been focused on addressing the problems of conventional data communication in WSN. Therefore, there exists an urgent need for research on the problems of multimedia communication in WSN. In this paper, a survey of the research challenges and the current status of the literature on the multimedia communication in WSN is presented. More specifically, the multimedia WSN applications, factors influencing multimedia delivery over WSN, currently proposed solutions in application, transport, and network layers, are pointed out along with their shortcomings and open research issues.

Keywords Data collection, Measurement sensor, Radiocommunication, Distributed system, Multimedia, Application layer, Transport layer, Network layer.

Communication architecture for processing spatio-temporal continuous queries in sensor networks

Ratnabali BISWAS, Neha JAIN, Nagesh NANDIRAJU, Dharma P. AGRAWAL

OBR Research Center for Distributed and Mobile Computing, ECECS Department, University of Cincinnati, Cincinnati, OH 452210030, USA

Abstract Wireless sensor networks have revolutionized distributed micro-sensing because of their ease of deployment, ad hoc connectivity and cost-effectiveness. They have also enabled collecting and monitoring data from a very large area or possibly several independent areas geographically separated from each other and such a process is known as spatio-temporal data monitoring. In this paper, we define an energy-aware routing infrastructure that enables distributed query processing and supports processing of spatio-temporal queries within the network. As operator execution demands high computation capability, we propose a possible use of a heterogeneous sensor network where query operators are assigned to sparsely-deployed resource-rich nodes within a dense network of low power sensor nodes. We have designed an adaptive, decentralized, low communication overhead algorithm to determine optimal operator placement on the resource-rich nodes such that data transfer cost in the network is minimized. To the best of our knowledge, this is the first attempt to build an energy-aware communication architecture to enable in-network processing of spatio-temporal queries.

Keywords Data collection, Measurement sensor, Radiocommunication, Distributed system, Heterogeneity, Adaptive algorithm, Database query, System architecture, Space-time processing, Research tree.

A semantic-based architecture for sensor networks

Qunhua PAN*, Minglu LI*, Lionel NI**, Min-You WU*,***

* Department of Computer Science and Engineering – Shanghai Jiao Tong University, Shanghai 200030, China.
** Department of Computer Science, Hong Kong University of Science and Technology – Clear Water Bay, Kowloon, Hong Kong.
*** Department of Electrical and Computer Engineering, The University of New Mexico, Albuquerque, New Mexico, USA.

Abstract With rapid development of sensor networks technology, it becomes feasible to deploy multiple sensor networks in relevant area to collect interested information. Sensor nodes that are colocated but belong to different sensor networks may not be able to collaborate properly to gain the capacity or performance. In this paper we propose a semantic-based sensor networks architecture that enables inter-networking of sensor networks. In this Semantic Sensor Net (SSN), a semantic tag is attached to the sensory data so that the sensor networks are able to exchange information and work collaboratively. The process of semantic creation and maintenance is described. We also introduce the concept of InterSensorNet. This infrastructure enables efficient information exchange and information extraction among multiple sensor networks.

Keywords Data collection, Measurement sensor, Radiocommunication, Network architecture, Semantics, Network interworking, Heterogeneity.

A taxonomy for medium access control protocols in wireless sensor networks

Luiz H. A. CORREIA1,2, Daniel F. MACEDO1, Aldri L. DOS SANTOS1,3, José Marcos NOGUEIRA1, *, Antonio A. F. LOUREIRO1

1. Computer Science Dpt., Univ. Federal de Minas Gerais, Av. Antonio Carlos, 6627, Pampulha, Belo Horizonte- MG, CEP 31270-901, Brazil.
2. Computer Science Dpt, Univ. Federal de Lavras – UFLA, Campus Universitário, Caixa Postal 3037, Lavras-MG, CEP 37200-000, Brazil.
3. Computer Science Dpt., Univ. Federal do Ceará, Av. da Universidade, 2583, Benfica, Fortaleza-CE, CEP 60020- 181, Brazil

Abstract Wireless sensor networks (WSNs) tend to be highly optimized due to severely restricted constraints. Various medium access control (MAC) protocols for WSNs have been proposed, being specially tailored to a target application. This paper proposes a taxonomy for the different mechanisms employed in those protocols. The taxonomy characterizes the protocols according to the methods implemented to handle energy consumption, quality of service and adaptability requirements. We also present an overview of the transceptors found in WSNs, identifying how events on communication affect the energy consumption. Based on the taxonomy, we classify existing MAC protocols. Finally, we discuss challenging trends in MAC protocols for WSNs, such as security issues and software radios.

Key words Data collection, Measurement sensor, Radiocommunication, Distributed system, Network protocol, Energy consumption, Taxonomy, MAC sublayer.

Data stream characterization and quality of service for future combat systems

Laurent ENEL*, Ludovic MARTINET**

* Université du Sud Toulon Var, lab sis/td, Institut des sciences de l’Ingénieur de Toulon et du Var – BP 56, 83162 La Valette Cedex, France
** Centre Technique des Systèmes Navals – BP 77, 83800 Toulon Naval, France

Abstract Futur combat systems will rely on the use of remote sensors to detect, identify and track targets. Embedded or deployed along coasts, these sensors generate data streams requiring various garanteed services from the networks. Sensor datas must be collected, processed and transported in a format making easy quick and accurate decisions. We focus on providing multiple quality of service (differentiated services) on a so called tactical internet.

Keywords Data collection, Measurement sensor, Distributed system, Military application, Internet, Data communication, Quality of service, Internet protocol, Network architecture.

Open Topics

Assembling components with behavioural contracts

Cyril CARREZ1,2, Alessandro FANTECHI3,4, Elie NAJM2

1. Department of Telematics, Norwegian University of Science and Technology, O. S. Bragstads plass 2B, N-7491 Trondheim, Norway
2. GET/Télécom Paris, Département INFRES, 46 rue Barrault, F-75013 Paris, France
3. Universita di Firenze, Dipartimento di Sistemi e Informatica, Via S. Marta 3, I-50139 Firenze, Italy
4. ISTI-CNR, Via G. Moruzzi 1, I-56124 Pisa, Italy.

Abstract Component based design is a new paradigm to build distributed systems and applications. The problem of compositional verification of such systems is however still open. We investigate methods and concepts for the provision of “sound” assemblies. We define a behavioural interface type language endowed with a (decidable) set of interface compatibilty and subtyping rules. We define an abstract, dynamic, multi-threaded, component model, encompassing both client/server and peer to peer communication patterns. Based on the notion of compliance of components to their interfaces, we define the concepts of “contract” and “contract satisfaction”. This leads to sound assemblies of components, which possess interesting properties, such as “external deadlock freeness” and “message consumption”.

Keywords System design, Component, Distributed system, Peer to peer networking, Client-server architecture, Software engineering, Type theory, Formal language, Compatibility, Bank institution.

Use of the process of renormalization for electromagnetic study of bi dimensional fractal structures


* Laboratoire Syscom, ENIT – BP 37, Le Belvédère, 1002 Tunis, Tunisie
** Laboratoire d’électronique, ENSEEIHT – 2 rue Charles Camichel, BP 7122, 31071 Toulouse cedex 7, France

Abstract In this article, we apply the renormalization technique, used possibly in theorical physics, for electromagnetic studying of bi dimensional fractal structures. A recurrence relation based on the auto-similar nature of structures and on the model of the surface impedance, has permitted, thanks to the convergence to a fixed point, to determine the input impedance of these structures at any scale. Though, the suggested method has been validated by calculus of one-dimensional structures (Iris de Cantor) it may be applied easily to the analysis of planar circuits as the Sierpensky antenna.

Key words Electromagnetism, Fractal system, Bidimensional system, Surface impedance, Renormalization, Iteration, Wave diffraction, Iris waveguide, Equivalent circuit.

Study in the time domain of a parabolic antenna radiation

Rodrigo de OLIVEIRA*, Marc HÉLIER**

* Laboratoire des Signaux et Systèmes (LSS)/Université de Versailles-St-Quentin, Plateau de Moulon, 3 rue Joliot Curie, 91192 Gif-sur-Yvette cedex, France
** Laboratoire des Instruments et Systèmes d’Ile-de-France (LISIF), Université Pierre et Marie Curie, 3 rue Galilée, 94200 Ivry-sur-Seine, France

Abstract This paper describes an original semi-analytic approach to study the field radiated by a parabolic reflector antenna. The method is an extension of Skulkin and Turchin’s work and is based on physical optics approximation in the time domain. Numerical results are presented to illustrate the efficiency of the method. It is noted that the fields can be provided in only a few seconds on a computer with a 400 MHz RISC processor. Numerical results are in good agreement with the finite-element time-domain method.

Keywords Parabolic antenna, Near field, Far field, Radiation pattern, Time domain method, Analytical method, Geometrical optics, Wave polarization, Impulse response, Calculating, time, Integral representation.

Low complexity syndrome algorithm for the decoding of convolutional codes

Jacques ANTOINE*, Lionel HUSSON*, Armelle WAUTIER*, Nicolas PAUL**, Jean-Claude DANY*, Jérôme BROUET**

* SUPELEC, École Supérieure d’Électricité, Dpt. Telecommunications, Plateau de Moulon, 91192 Gif-sur-Yvette, France
**Alcatel Research and Innovation, Route de Nozay, 91461 Marcoussis cedex, France

Abstract The decoding of convolutional codes in the maximum likelihood sense is carried out in a traditional way with the Viterbi algorithm (VA). We proposed a soft and hard input decoder where the VA, associated with an relevant metric, is applied to identify the error vector rather than the information message. In this paper, we show that, with this type of decoding, the exhaustive computation of a majority of ACS (Add Compare Select) is unnecessary. Moreover, we show that optimal performance is achieved in the case of a hard input decoder, and that performance closed to the optimum is achieved in the case of a soft input decoder, while offering of a reduction of the complexity which is all the more important than the Ec/No ratio is high (e. g. for ratio Ec/No greater than 3 dB, more than 80 % of the ACS can be avoided). We also propose an algorithm allowing rejecting a frame without having to carry out any iteration of the VA.

Keywords Error correcting code, Convolutional code, Decoding, Computing complexity, Viterbi decoding, Simulation.