SENSORNETS 2012 Abstracts


Area 1 - Sensor Networks Software and Architectures

Full Papers
Paper Nr: 6
Title:

HUMAN PRESENCE DETECTION USING RADIO IRREGULARITY IN WIRELESS NETWORKS - Human Detection in Energy Aware Residential Networks

Authors:

Bojan Mrazovac, Milan Z. Bjelica, Dragan Kukolj, Branislav M. Todorović and Saša Vukosavljev

Abstract: The paper presents a human detection method applied to the intelligent device-level software platform for residential energy management. The proposed solution increases user awareness and automates the power control, with the primary goal to contribute in energy savings. Instead of using conventional presence sensors as inputs for automated power management, the proposed solution utilizes a network of wireless power outlets and monitors the variations of the signal strength indicator used for the communication between them. The radio signals used for the inter-outlets communication can be scattered, absorbed or reflected by objects in their propagation paths, such as a human body which additionally increases the variation of the signal strength indicator at the receiver. This phenomenon is known as radio irregularity, and is often considered as a shortcoming of radio networks. In this paper the idea of using radio irregularity as efficient presence detection is proposed. With regard to conventional sensors, this solution preserves the pervasiveness of smart energy and smart home systems, high level of sensorial intelligence and low installation costs.

Paper Nr: 8
Title:

REDUNDANT DISTRIBUTED DATA STORAGE - Experimentation with the SensLab Testbed

Authors:

Pietro Gonizzi, Gianluigi Ferrari, Vincent Gay and Jérémie Leguay

Abstract: Wireless sensor network (WSN)-based applications typically require to store data in the network. For instance, in the surveillance of isolated areas, if no sink nodes are present, WSNs may archive observation data that are periodically retrieved by an external agent. In contrast to conventional network data storage, storing data in WSNs is challenging because of the limited power, memory, and communication bandwidth of WSNs. In our study, we review the state-of-art techniques for data replication and storage in WSNs, and we propose a lowcomplexity distributed data replication mechanism to increase the resilience of WSN storage capacity against node failure and local memory shortage. We evaluate our approach through experimental results collected on the SensLab large-scale real testbed. In particular, we show how the performance is affected by changing the configuration of several key system parameters, such as (i) the transmission power of the nodes; (ii) the control message overhead; (iii) the number of deployed nodes; and (iv) the redundancy. To the best of our knowledge, this is one of the first works presenting experimental results at a really large scale on SensLab.

Paper Nr: 12
Title:

FAST TRANSPARENT VIRTUAL MEMORY FOR COMPLEX DATA PROCESSING IN SENSOR NETWORKS

Authors:

Nan Lin, Yabo Dong and Dongming Lu

Abstract: Sensor networks has been used in numerous fields, some of which require complex processing of large amount of data, such as visual surveillance. Low-power MCUs on sensor nodes have kilobytes of RAM which is not enough for mass data processing. In this paper, we present a transparent software-based virtual memory for mass complex data processing in sensor networks which can be much larger than the physical memory. Traditional optimizations have been employed and tuned to best suit the virtual memory. Address translations were found to be a major overhead in virtual memory for most applications. With respect to assembly conversion commonly used in other software-based virtual memory systems, we use flexible C code transformation which generates cache index buffers to greatly reduce the address translation overhead. The usability of the virtual memory is further verified by a number of common algorithms using the virtual memory.

Paper Nr: 35
Title:

CHANNEL AND ACTIVE COMPONENT ABSTRACTIONS FOR WSN PROGRAMMING - A Language Model with Operating System Support

Authors:

Paul Harvey, Alan Dearle, Jonathan Lewis and Joseph Sventek

Abstract: To support the programming of Wireless Sensor Networks, a number of unconventional programming models have evolved, in particular the event-based model. These models are non-intuitive to programmers due to the introduction of unnecessary, non-intrinsic complexity. Component-based languages like Insense can eliminate much of this unnecessary complexity via the use of active components and synchronous channels. However, simply layering an Insense implementation over an existing event-based system, like TinyOS, while proving efficacy, is insufficiently space and time efficient for production use. The design and implementation of a new language-specific OS, InceOS, enables both space and time efficient programming of sensor networks using component-based languages like Insense.

Short Papers
Paper Nr: 5
Title:

USING PROVENANCE IN SENSOR NETWORK APPLICATIONS FOR FAULT-TOLERANCE AND TROUBLESHOOTING - Position Paper

Authors:

Gulustan Dogan and Theodore Brown

Abstract: Provenance is a rapidly progressing new field with many open research problems. Being related to data and processes, provenance research is at the cross-roads of research from several research communities. With the huge amount of information and processes available in sensor networks, provenance becomes crucial for understanding the creation, manipulation and quality of data and processes in this domain too. Sensors collaboratively carry out sensing tasks and forward their data to the closest data processing center, which may further forward it. Provenance provides the means to record the data flow and manipulate snapshots of the network. Consequently given enough data, provenance can be used in sensor network applications to find out causes of faulty behavior, to figure out the circumstances that will affect the performance of the sensor network, to produce trustworthy data after elimination of the causes, etc. In this position paper, we describe provenance work in the sensor network community to sketch a panoramic view of the recent research and give a provenance model of a binary target localization sensor network as a real life example to show how provenance can be used in sensor network applications for fault-tolerance and troubleshooting.

Paper Nr: 21
Title:

PicOS & VNETI - Enabling Real Life Layer-less WSN Applications

Authors:

Nicholas M. Boers, Ioanis Nikolaidis, Pawel Gburzynski and Wlodek Olesinski

Abstract: In the simple devices used for wireless sensor networks, the costs associated with a layered approach can be significant. Small-footprint operating systems have been developed by adopting non-traditional approaches to network abstractions while still aiming to simplify software development. In these approaches, some elements of modularity are valuable to retain, e.g., packet buffer management, which can be factored out of the layers and supported by a generic interface. In this paper, we describe the PicOS operating system with its versatile network interface (VNETI) and describe our experience using it. VNETI’s approach to the problem, where it acts as a mediator between (a) the application programming interface, (b) protocol plug-ins, and (c) a physical input/output module, allows for an effective component-based design with low overheads. With our essentially layer-less approach to networking, we have found it intuitive to incorporate even the simplest devices into nontrivial networks.

Paper Nr: 26
Title:

NETWORK PLANNING TOOL WITH TRAFFIC-ADAPTIVE PROCESSING FOR WIRELESS SENSOR NETWORKS

Authors:

José Cecílio and Pedro Furtado

Abstract: Some applications of Wireless sensor networks (WSNs), especially in industrial sense and react scenarios, require fairly fast sampling rates. Considering that a few sensors may share a common sink, sharing part of their path on the way to the sink may result in undesirable message losses and delays that cannot be solved without modifying data communication rates. Our research focuses on planning a WSN to avoid excess traffic during sensing and acting to guarantee the minimal delay for critical scenarios. In this paper we propose an integrated approach to plan, test and reconfigure a network. Initially, our approach gives guidance for a base-plan for the network. With this first-cut plan we test the performance of the network and if necessary reconfigure it. The results of tests given are followed by traffic-level adjustments of the system by several possible techniques: adjustment of number of nodes, network partitions, reduction of the sampling rate or in-network processing with strategies such as aggregation techniques or in-node closed control loops. We evaluate experimentally the proposed approach with two different mechanisms of communication, and different levels of traffic, showing that our planning and reconfiguration allows users to make the best choices for the application context.

Paper Nr: 37
Title:

TandemStack - A Flexible and Customizable Sensor Node Platform for Low Power Applications

Authors:

Oliver Stecklina, Dieter Genschow and Christian Goltz

Abstract: Wireless sensor nodes are becoming more and more considered for a wide variety of application scenarios. But by going into real world scenarios requirements becomes more complex and must be covered more accurate. Furthermore, these requirements must be met by a development process that is driven by the factors of cost and time. Reusing components is a promising way to make such a development process more efficient. We present a flexible and customizable sensor node platform which follows the objective to assemble as few functional units as possible on a single Printed Circuit Board (PCB). The PCBs are connected by a standardized board-to-board connector, which makes a free ordering and mixture of different modules possible. We will show that by using a standardized Mote Component Interconnect (MCI) an extension as well as an adaption of a sensor node to new scenarios becomes feasible by adding or replacing single platform components. The presented sensor node platform allows a fast and inexpensive development process as is necessary for current and upcoming real word applications.

Paper Nr: 41
Title:

MUTUAL EXCLUSION IN CYBER-PHYSICAL SYSTEMS

Authors:

Sumeet Gujrati and Gurdip Singh

Abstract: Distributed computing problems such as mutual exclusion have been studied extensively for traditional distributed systems. In traditional systems, a strict layered approach is taken wherein a set of users (application processes) U1; : : : ;Un is layered on top of a mutual exclusion algorithm with processes P1; : : : ;Pn. User Ui interacts with process Pi to request access to resources which are modeled as tokens, and users rely entirely on mutual exclusion algorithm to regulate access to the resources. In a cyber-physical system, users (physical entities) may themselves possess capabilities such as sensing, observing and mobility using which they may also attempt to locate physical resources such as wheelchairs. Thus, a mutual exclusion algorithm in a cyber-physical system must contend with the behavior of users. This paper proposes a graph-based model for cyber-physical systems which is used to describe mutual exclusion algorithm as well as user behavior. Based on this model, we present several solutions for the mutual exclusion problem. We have also conducted an extensive simulation study of our algorithms using OMNeT++ discrete event simulation system.

Posters
Paper Nr: 18
Title:

SECURE DELIVERY OF DATA IN WSN

Authors:

Ibrahim Kamel and Hussam Juma

Abstract: This paper proposes FWC- a hash-based fragile watermarking technique to protect the integrity of sensor data. Sensor data are organized into groups before calculating the hash digest and storing them in the least significant bits. The watermark is chained across the groups to mitigate group insertion and deletion attacks. Detailed security analysis is provided for each of the proposed scheme. Experimental results prove that the proposed schemes are much faster than SGW security technique. At the same time, the proposed schemes are more robust than SGW.

Paper Nr: 28
Title:

MOBILITY ASSISTED COVERAGE RESTORATION SCHEME IN WIRELESS SENSOR NETWORKS

Authors:

Eman AlQuraishi, Paulvanna N. Marimuthu and Sami J. Habib

Abstract: In this paper, we have examined the problem of simultaneous failure of sensors within the wireless sensor networks (WSN), whereby the sensors failures are due to malfunction or electrical faults. We have proposed a mobility assisted coverage restoration algorithm, which restores the coverage of the failed sensors without adding new sensors. The proposed algorithm follows two phases; clustering and restoration. The clustering phase groups the failed sensors with their proximity, and then it relocates them into cluster. The restoration phase moves the nearby active sensor with higher energy to the center of the cluster of failed sensors and doubles its sensing area to restore the coverage. The restoration scheme exploits the mobility of the sensors to form clusters of failed sensor, which reduce the number of restoring sensors, thereby prolonging the lifespan of the network. Experimental results indicate that for a small size WSN comprising of 25 nodes and nine nodes of it failing simultaneously, our restoration algorithm is able to increase the coverage area from 34% to 86% at the expense of small reduction in the lifespan estimated to be 24% of the network.

Paper Nr: 44
Title:

ON-LINE MONITORING OF BATTERY STATE IN WIRELESS SENSOR NETWORKS - Using Two Battery Models in WSN Constraints

Authors:

Anania Aron, Gabriel Girban and Mircea Popa

Abstract: This paper addresses the class of wireless sensor networks where the nodes are using batteries as power sources. It describes the adaptation of an existing analytical battery model to fit the constraints of the wireless sensors in terms of available resources, the algorithm complexity being reduced to O(n) in case of constant loads. The analytical battery model obtained is used together with another existing battery model to provide real time information about the remaining capacity of the battery, based on the electric current draw and elapsed time. The current consumption is estimated using application specific power profiles, thus the monitoring solution proposed does not imply additional hardware on a mote and can be used on each node of a WSN during network employment as a real time decision support.

Paper Nr: 54
Title:

TOWARDS INCREASING THE REUSABILITY OF THE WIRELESS SENSOR NETWORK PROTOCOLS

Authors:

Sonia Hashish

Abstract: Increasing the reusability of the wireless sensor network protocols requires decoupling the underlying communication primitives from the upper layer protocols primitives. One way to achieving this goal is unifying the whole software stack architecture. This unifying process would significantly increase the overhead and affect the resulting performance. It is still unknown whether this huge unifying process will provide the required benefits to the protocol designers. Building a generic infrastructure at the level of physical links is a promising step towards increasing the reusability of upper layer protocols. To be described as a generic, the infrastructure should efficiently support different upper layer protocols and different communication configurations. It should also provide logical relationships among nodes without hiding the physical relationships. Moreover, Failures should neither destruct the infrastructure nor hinder the upper layer operations. Building such infrastructure is very challenging and is still an open research problem.

Paper Nr: 55
Title:

SELF-SUSTAINING LEARNING FOR ROBOTIC ECOLOGIES

Authors:

D. Bacciu, M. Broxvall, S. Coleman, M. Dragone, C. Gallicchio, C. Gennaro, R. Guzmán, R. Lopez, H. Lozano-Peiteado, A. Ray, A. Renteria, A. Saffiotti and C. Vairo

Abstract: The most common use of wireless sensor networks (WSNs) is to collect environmental data from a specific area, and to channel it to a central processing node for on-line or off-line analysis. The WSN technology, however, can be used for much more ambitious goals. We claim that merging the concepts and technology of WSN with the concepts and technology of distributed robotics and multi-agent systems can open new ways to design systems able to provide intelligent services in our homes and working places. We also claim that endowing these systems with learning capabilities can greatly increase their viability and acceptability, by simplifying design, customization and adaptation to changing user needs. To support these claims, we illustrate our architecture for an adaptive robotic ecology, named RUBICON, consisting of a network of sensors, effectors and mobile robots.

Area 2 - Wireless Information Networks

Short Papers
Paper Nr: 23
Title:

BROWSING THE SENSOR WEB - Pervasive Access for Wide-area Wireless Sensor Networks

Authors:

Jie Wan, Michael J. O'Grady, Gregory M. P. O'Hare and Todor Colakov

Abstract: Wireless Sensor Networks (WSNs) are almost exclusively regarded as data gathering entities. Various sensed data elements are captured and routed back to a central server for processing, visualization and interpretation. However, it can be realistically conjectured that scenarios will increasingly emerge that demand a facility for ad-hoc interaction with individual sensor nodes. Moreover, such interaction will occur in the physical environment in close proximity to where the sensor node is physically located. In this paper, the need for in-situ ad-hoc interaction is motivated. A methodology for facilitating such interaction is presented, and the implementation of a sensor browser is described.

Posters
Paper Nr: 40
Title:

ENERGY/LATENCY TRADE-OFFS IN GEOGRAPHIC ROUTING FOR ULTRAWIDEBAND WIRELESS SENSOR NETWORKS

Authors:

Samuela Persia and Dajana Cassioli

Abstract: Wireless Sensor Networks (WSNs) may exploit accurate localization capabilities of ultrawideband (UWB) transceivers to improve performance of high layer protocols. We analyze power consumption of a WSN accommodating both communication and positioning into the same UWB transceiver and implementing a geographic routing algorithm, either the Greedy Perimeter Stateless Routing (GPSR) or its energy aware version, the e-GPSR. Power consumption depends on beacon rate for positions’ updates, the number of hops to reach the destination and the number of neighbors per node. On the other hand, the beacon rate impacts the reliability of the neighbor lists; the number of hops impacts on the end-to-end latency; the number of neighbors, i.e. the network connectivity, impacts on routing performance. The presented analysis assesses, by means of both theoretical investigations and simulation results, the main trade-offs between power consumption and latency that can be applied to obtain the best achievable performance.

Paper Nr: 46
Title:

DIFFUSION BEHAVIOR OF IEEE 802.15.4 UNSLOTTED CSMA/CA IN A CELL OF PROXIMITY-BASED LOCALIZATION APPLICATIONS

Authors:

Chakib Baouche, Antonio Freitas and Michel Misson

Abstract: This paper relates to a generic solution for localization and tracking applications usingWireless sensor network in confined areas where the GPS technology is no longer functional. The proposed solution exploits node mobility by allowing stations to come into contact with other fixed or mobile stations to collect, transmit and pass around their knowledge, which is a collection of ’contact events’. Each contact event being a way to record the fact that a node has been in range of an another node. This event can also refer to a geographical location. The amount of contact events that have been created depends on the effectiveness of the contact detection mechanism and on the performance of the WSN medium access method. This leads us to study the performance of IEEE 802.15.4 unslotted CSMA/CA when the offered load of a cell is only broadcast traffic. Frames are not always received because of collisions or of unsuccessful transmission attempts. This leads to a rupture of the current contact involving the creation of useless contact events for the same situation of proximity between entities. The results obtained by simulation, determine the capability of a cell in terms of number of mobiles and size of the exchanged frames for an acceptable rate of false contact detection.

Area 3 - Hardware

Full Papers
Paper Nr: 30
Title:

LIGHTWEIGHT AUTHENTICATION PROTOCOLS BASED ON ROTATIONS AND THE LPN PROBLEM

Authors:

Alberto Peinado and Jorge Munilla

Abstract: Many lightweight authentication protocols based on the LPN (Learning Parity with Noise) problem have been proposed, the first of which is the HB protocol. In 2007, the HB-MP protocol was presented to overcome the vulnerabilities by means of internal rotations. Since then, new protocols have been presented to improve the HB-MP. In this paper, we present a general analysis of the HB-MP related protocols, including the cryptanalysis of HB-MP++, define design guidelines and propose a new protocol following the model.

Area 4 - Data Manipulation

Full Papers
Paper Nr: 11
Title:

PEDESTRIAN DEAD RECKONING AS A COMPLEMENTARY METHOD FOR WIRELESS SENSOR NETWORK AD-HOC PERSON LOCALIZATION

Authors:

Tobias Gädeke, Johannes Schmid, Wilhelm Stork and Klaus D. Mueller-Glaser

Abstract: The problem of localization and navigation in areas without any or with only limited access to global navigation satellite systems (GNSS) is still not solved. This is especially the case for person localization applications as persons tend to spend a good part of their time in buildings or in cities (urban canyons). One possibility to approach this issue is to use wireless sensor network (WSN) technology. Especially scenarios that require ad-hoc person localization like firefighters that enter a burning building or similar setups, WSN seem to be a promising solution. However, if the node density is low or if the scenario also requires localization in uncovered areas, an additional localization method is required. Pedestrian dead reckoning (PDR) is an ideal complementary method to achieve short term accurate localization under these assumptions. In this paper, an approach to PDR with low processing power for the use in WSN with a hip mounted inertial measurement unit (IMU) is presented. The purpose of the system is to provide a localization and tracking solution if temporarily none or only few anchor nodes are within communication range. This is achieved by detecting steps, estimating the length of each step and determining the step direction in WSN coordinates. We experimentally evaluate the system under varying environmental conditions and show that the concept is a promising solution for the intended applications.

Posters
Paper Nr: 4
Title:

A RELATIONAL DATABASE AND KEY-VALUE STORE COMBINED MECHANISM FOR MASSIVE HETEROGENEOUS SENSOR DATA MANAGEMENT

Authors:

Zhiming Ding, Qi Yang and Limin Guo

Abstract: Massive sensor data management is an important issue in large-scale sensor based systems such as the Internet/web of Things. However, existing relational database and cloud data management techniques are inadequate in handling large-scale sensor sampling data. On the one hand, relational databases can not efficiently process frequent data updates caused by sensor samplings. On the other hand, current cloud data management mechanisms are largely key-value stores so that they can not support complicated spatial-temporal computation involved in sensor data query. To solve the above problems, we propose a Relational Data-Base and Key-Value store combined Cloud Data management (“RDB-KV CloudDB”) framework, in this paper. The experimental results show that the RDB-KV CloudDB can provide satisfactory query processing and sensor data updating performances in large scale sensor-based systems.

Area 5 - Signal Processing

Full Papers
Paper Nr: 29
Title:

SOUND LOCALIZATION USING COMPRESSIVE SENSING

Authors:

Hong Jiang, Boyd Mathews and Paul Wilford

Abstract: In a sensor network with remote sensor devices, it is important to have a method that can accurately localize a sound event with a small amount of data transmitted from the sensors. In this paper, we propose a novel method for localization of a sound source using compressive sensing. Instead of sampling a large amount of data at the Nyquist sampling rate in time domain, the acoustic sensors take compressive measurements integrated in time. The compressive measurements can be used to accurately compute the location of a sound source.

Short Papers
Paper Nr: 47
Title:

THE SQUARE-ROOT UNSCENTED INFORMATION FILTER FOR STATE ESTIMATION AND SENSOR FUSION

Authors:

Guoliang Liu, Florentin Wörgötter and Irene Markelić

Abstract: This paper presents a new recursive Bayesian estimation method, which is the square-root unscented information filter (SRUIF). The unscented information filter (UIF) has been introduced recently for nonlinear system estimation and sensor fusion. In the UIF framework, a number of sigma points are sampled from the probability distribution of the prior state by the unscented transform and then propagated through the nonlinear dynamic function and measurement function. The new state is estimated from the propagated sigma points. In this way, the UIF can achieve higher estimation accuracies and faster convergence rates than the extended information filter (EIF). As the extension of the original UIF, we propose to use the square-root of the covariance in the SRUIF instead of the full covariance in the UIF for estimation. The new SRUIF has better numerical properties than the original UIF, e.g., improved numerical accuracy, double order precision and preservation of symmetry.

Posters
Paper Nr: 36
Title:

CONTROLLING CHAOTIC INSTABILITIES IN BRILLOUIN FIBER SENSOR BASED ON NEURAL NETWORKS

Authors:

Tae- Su Jnag, Kwan-Woong Kim and Yong K. Kim

Abstract: In this paper the neuron operation based on neural network in optical fibre system has described. The inherent feedback wave in optical fibre leads to instabilities in the form of optical chaos. Below threshold value temporal evolution has periodic and can become chaotic condition. Controlling of chaotic induced transient instability in Brillouin fibre sensor has been implemented with Kerr nonlinearity with 13GHz backward shift, IR detector with 20ps impulse response, and ~10ns round trip time in optical network. The detected sensor has up-shifted in frequency by about ~20MHz from sensing target. The Controlling chaotic instabilities can lead to stable and periodical states; create optical logic data streams. It can lead to large optical memory capacity in neural networks.

Area 6 - Obstacles

Full Papers
Paper Nr: 9
Title:

UHEED - An Unequal Clustering Algorithm for Wireless Sensor Networks

Authors:

E. Ever, R. Luchmun, L. Mostarda, A. Navarra and P. Shah

Abstract: Prolonging the lifetime of wireless sensor networks has always been a determining factor when designing and deploying such networks. Clustering is one technique that can be used to extend the lifetime of sensor networks by grouping sensors together. However, there exists the hot spot problem which causes an unbalanced energy consumption in equally formed clusters. In this paper, we propose UHEED, an unequal clustering algorithm which mitigates this problem and which leads to a more uniform residual energy in the network and improves the network lifetime. Furthermore, from the simulation results presented, we were able to deduce the most appropriate unequal cluster size to be used.

Short Papers
Paper Nr: 31
Title:

COEXISTENCE OF DIFFERENT WIRELESS SENSOR NETWORKS - MAC Protocol Interference between X-MAC and Low Power Probing

Authors:

Sven Zacharias, Thomas Newe, Sinead O’Keeffe and Elfed Lewis

Abstract: Wireless Sensor Networks (WSNs) are an emerging technology that will be widely deployed in the near future. Most WSNs operate on the 2.4 GHz band of the three free ISM frequency bands. The 2.4 GHz frequency band is already used by different wireless systems. With an increasing number of WSNs, the scenario of different WSNs operating on the same IEEE 802.15.4 frequency channel becomes more likely. WSN Medium Access Control (MAC) Protocols used today were not designed with this problem in mind. To date, the research focused on interference on the Physical Layer. This work analyses the jamming potential and the robustness of MAC Protocols, namely X-MAC and Low Power Probing (LPP), at the level of inter-network competition for medium access, when multiple WSNs are in range of each other operating on the same channel. The following parameters have been investigated and their effect on interference is shown: sampling time, channel check rate and payload.

Paper Nr: 51
Title:

CROSS LAYER DATA ASSESSMENT IN WIRELESS SENSOR NETWORKS

Authors:

Alberto Coen Porisini and Sabrina Sicari

Abstract: Wireless sensor networks (WSN) are the target of different kinds of security attacks. The network nodes, which sense, aggregate, encrypt and transmit data, play a key role for assuring data quality. In this paper we present a way in which the network sink can evaluate the nodes reputation in order to determine whether one or more nodes are behaving maliciously. The approach combines different techniques such secure localization and privacy aware transmission in order to assess both nodes reputation and data quality.

Area 7 - Applications and Uses

Full Papers
Paper Nr: 38
Title:

A MULTI-SENSOR SYSTEM FOR FALL DETECTION IN AMBIENT ASSISTED LIVING CONTEXTS

Authors:

Giovanni Diraco, Alessandro Leone, Pietro Siciliano, Marco Grassi and Piero Malcovati

Abstract: The aging population represents an emerging challenge for healthcare since elderly people frequently suffer from chronic diseases requiring continuous medical care and monitoring. Sensor networks are possible enabling technologies for ambient assisted living solutions helping elderly people to be independent and to feel more secure. This paper presents a multi-sensor system for the detection of people falls in home environment. Two kinds of sensors are used: a wearable wireless accelerometer with onboard fall detection algorithms and a time-of-flight camera. A coordinator node receives data from the two sub-sensory systems with their associated level of confidence and, on the basis of a data fusion logic, it operates the validation and correlation among the two sub-systems delivered data in order to rise overall system performance with respect to each single sensor sub-system. Achieved results show the effectiveness of the suggested multi-sensor approach for improving fall detection service in ambient assisted living contexts.

Short Papers
Paper Nr: 20
Title:

PRIVACY-PRESERVING IN-NETWORK AGGREGATION IN WIRELESS SENSOR NETWORK

Authors:

Wei Zha and Wee Keong Ng

Abstract: Ubiquitously deployed wireless sensor networks provide grate conveniences for environment monitoring. However, it also brings the risk of violating privacy. Sensitive sensor data disclosed to malicious part may cause unexpected lost. In this paper, we propose a privacy-preserving in-network aggregation protocol for wireless sensor network based on the concept of data slicing, mixing and merging with a novel share key management scheme. Our protocol allows performing in-network aggregation in sensor network while keeps the privacy of participates. Although we only study additive aggregation in this paper, our protocol can be easily extended to other aggregation functions, including average, count and many other functions based on aggregation as long as these aggregation functions can be reduced to additive aggregation function. Performance evaluation yields the efficiency and effectiveness of our protocol.

Paper Nr: 53
Title:

SATELLITE OBSERVATION OF BARE SOILS FOR THEIR AVERAGE DIURNAL ALBEDO APPROXIMATION

Authors:

Jerzy Cierniewski

Abstract: This study explores the diurnal variation in broadband blue-sky albedo () of soils with respect to their roughness. Uncultivated soils and cultivated ones, after ploughing, harrowing and rolling were studied in Israel and Poland. The relation between of the surfaces and the solar zenith angle allowed to predict the diurnal  variation of the surfaces located at a given latitude at any date, and calculate the optimal time TO related to their average diurnal albedo observation. This procedure was used to assess the usefulness of satellites on the sun-synchronous orbits for approximation of for the moderately rough bare soil surfaces, located between the latitude angles of 75° S to 75° N, within an error lower than ±2%. It was found that the satellites on the orbits crossing the Equator at 10:30, such as the MODIS, and like the SPOT and IRS IC, are not very useful for that, while the NOAA-15 on the orbit crossing the Equator at 7:30 is much more useful. The best dates for the collection of data with this satellite are 16 April and 28 August, while the worst date is June 22.

Posters
Paper Nr: 39
Title:

UNCERTAINTY IN TRILATERATION - Is RSSI-based Range Estimation Accurate Enough for Animal Tracking?

Authors:

Ragnar Stølsmark and Erlend Tøssebro

Abstract: Animal tracking is important to farmers. It is mainly performed using GPS receivers. Equipping only some of the animals with GPS receivers and have the others use them as beacons for RSSI-based trilateration could be beneficial. This article tests whether such a solution is possible from an uncertainty point of view. First a range of RSSI measurements were performed. These measurements were used to create a formula for RSSI as a function of distance. The RSSI standard deviation measured in the tests gave an indication of the error, or uncertainty, related to using RSSI to calculate distance. The distance function and standard deviation were then used as a basis for simulations that calculated the uncertainty of RSSI-based range estimation. The simulations showed that the localization error related to distance estimation by RSSI was too high for it to be an efficient solution, even with a device twice as accurate as the test device.