Antonio Manes

Energy efficient routing algorithms for application to agro-food wireless sensor networks

Precision agriculture (PA) represents a novel paradigm for managing agro-food production, by monitoring the physical parameters of different farming zones. This might be pursued by means of different communication infrastructures, but the most promising technology seems to be the wireless sensor network (WSN). However, merely applying this approach to the PA context, while resulting in a more flexible communication platform, still exhibits a rigid information management architecture. This limitation can be overcome by applying the ambient intelligent (AmI) paradigm to create an environment highly interactive with all the users involved in the process. Our proposal deals with the porting of the AmI concepts on a highly-integrated WSN platform with a special focus on the routing strategies. In particular, we investigate a class of dynamic flooding algorithm which is aware of the status of neighbor nodes in terms of geographical position and residual battery charge. By comparing this approach with the gossiping and the static flooding schemes, we are able to highlight a remarkable improvement in the network life-time with a particular regard to the most solicited nodes, without increasing complexity.

Agricultural Monitoring Based on Wireless Sensor Network Technology: Real Long Life Deployments for Physiology and Pathogens Control

Today Wireless Sensor Network are used into an increasing number of commercial solutions, aimed at implementing distributed monitoring and control system in a great number of different application area. In particular the agricultural scenario seems to be one of the most promising application area for WSN due to the necessity of proving the agricultural production chain in terms of precision and quality. This involves a careful system design, since requirements are very strict: battery life-time maximization,robustness, recovery strategies, network flexibility and reconfigurability. This paper shows and describes a practical case study, starting from a real problem and reaching the best architectural solution, with particular focus on the hardware implementation and communication protocol design. A real end-to-end solution has been implemented: several wireless nodes send environmental data every 15 minutes to a master node connected to a GPRS gateway board that forwards data to a remote server using TCP-IP standard protocol. The encouraging and unprecedented results achieved by this approach are supported by several pilot sites into different vineyard in Italy and in France, within which a great amount of environmental data have been collected and analyzed since two years and half.

Enhanced System Design Solutions for Wireless Sensor Networks applied to Distributed Environmental Monitoring

We study the performance of several search algorithms on unstructured peer-to-peer networks, both using classic search algorithms such as flooding and random walk, as well as a new hybrid algorithm proposed in this paper. This hybrid algorithm first uses flooding to find sufficient number of nodes and then starts random walks from these nodes. We compare the performance of the search algorithms on several graphs corresponding to common topologies proposed for peer- to-peer networks. In particular, we consider binomial random graphs, regular random graphs, power-law graphs, and clustered topologies. Our experiments show that for binomial random graphs and regular random graphs all algorithms have similar performance. For power-law graphs, flooding is effective for small number of messages, but for large number of messages our hybrid algorithm outperforms it. Flooding is ineffective for clustered topologies in which random walk is the best algorithm. For these topologies, our hybrid algorithm provides a compromise between flooding and random walk. We also compare the proposed hybrid algorithm with the fc-walker algorithm on power-law and clustered topologies. Our experiments show that while they have close performance on clustered topologies, the hybrid algorithm has much better performance on power-law graphs. We theoretically prove that flooding is effective for regular random graphs which is consistent with our experimental results.The adoption of wireless sensor networks (WSN) for wide area environmental monitoring is currently considered one of the most challenging application scenario for this emerging technology. The promise of an unmanaged, self-configuring and self-powered wireless infrastructure, with a continuously decreasing cost per unit, attracts the attention of both final users and system integrators, replacing previously deployed wired solutions and opening new business opportunities. This challenge might be afforded by resorting to a complete system level design to jointly address and optimize all the involved aspects. Besides, the design guide lines need to be inspired by the application requirements rather than technology driven. Following this approach, this paper presents an overall solution focusing both on node, network and remote user interface issues. The proposed platform in finally applied to a realistic user defined scenario oriented to agro-food production phase monitoring within GoodFood Integrated Project. The results of the validation phase presented highlight remarkable advantages both in terms of cost and complexity reduction and experienced QoS enhancement as well and, consequently, validating the WSN technology adoption.

A Wireless Sensor Network for Precise Volatile Organic Compound Monitoring

A variety of methods have been developed to monitor VOC concentration in hazardous sites. The methods range from calculation to measurement, point measuring to remote sensing. Some are suited for leak detection, others for estimation of the annual emission or both. None of the following available methods comes close to the ideal method. A distributed instrument providing precise monitoring of Volatile Organic Compound (VOC) concentration in a petrochemical plant is described; it consists of a Wireless Sensor Network (WSN) platform whose nodes are equipped with meteorological/climatic sensors and VOC detectors. Internet connectivity is provided in real time at a one-minute sampling rate, thus providing environmental authorities and plant management with an unprecedented tool for immediate warning in case of critical events. The paper describes the WSN platform, detailing various units (gateways, nodes, detectors) and shows the features of scalability and reconfigurability, with minimal intrusiveness or obtrusiveness. Environmental and process data are forwarded to a remote server and made available to the authenticated users through a rich user interface that provides data rendering in various formats and worldwide access to data. A survey of the VOC detector technologies involved is also provided.

Design and Application of Enhanced Communication Protocols for Wireless Sensor Networks operating in Environmental MonitorinDg

The adoption of Wireless Sensor Networks (WSN) for wide area environmental monitoring is currently considered one of the most challenging application scenario for this emerging technology. The promise of an unmanaged, self-configuring and self-powered wireless infrastructure attracts the attention of both final users and system integrators, replacing previously deployed wired solutions and opening new business opportunities. Even if many habitat monitoring applications usually do not provide for strictly real-time performances, however, smart power saving procedures have to be adopted, especially to increase the network lifetime. A common approach is to introduce a low power sleep mode, in which the nodes radio section is switched off. In adhoc networking scenarios, this definitely requires the adoption of synchronization procedures, properly scheduling the packet transmission time and avoiding both overhearing effects and collisions. In this paper, a novel class of MAC layer protocols, named STAR MAC, that aims at efficiently managing the nodes low power mode, is presented, and properly integrated within a routing scheme, according to the cross-layer design for minimizing the signaling overhead. The proposed solution is applied to a realistic user defined scenario oriented to agro-food production phase monitoring, highlighting remarkable advantages both in terms of cost and complexity reduction and QoS enhancement as well and, consequently, validating the WSN technology adoption.

A Distributed Sensor Network for Real-Time Acoustic Traffic Monitoring and Early Queue Detection

A novel sensor network configuration is introduced for traffic surveillance in Intelligent Transportation Systems. Distributed sensor nodes based on passive acoustic transducers are non intrusively/obtrusively deployed at motorway road-side to provide real-time traffic data collection for dynamic queue/jam detection. The system is capable to provide a complete real-time picture of traffic flow at unprecedented time/space scale. The infrastructure is based on a stand-alone, install-and-forget architecture, featuring an energy efficient protocol for sensor networking and providing connectivity to back-end computing environment via TCP/IP over UMTS. Extensive experimental demonstration is given for long term operation on a motorway test site.

Efficient MAC Protocols for Wireless Sensor Networks Endowed with Directive Antennas: A Cross-Layer Solution

This paper deals with a novel MAC layer protocol, namely, directive synchronous transmission asynchronous reception (D-STAR) able to space-time synchronize a wireless sensor network (WSN). To this end, D-STAR integrates directional antennas within the communications framework, while taking into account both sleep/active states, according to a cross-layer design. After characterizing the D-STAR protocol in terms of functional characteristics, the related performance is presented, in terms of network lifetime gain, setup latency, and collision probability. It has shown a remarkable gain in terms of energy consumption reduction with respect to the basic approach endowed with omnidirectional antennas, without increasing the signaling overhead nor affecting the setup latency.

A real-time traffic monitoring based on wireless sensor network technologies

Non intrusive systems-based traffic monitoring, is a paradigm for Intelligent Transportation Systems (ITS). Real time systems capable of providing prompt information, like loop detectors, laser/radar systems and video cameras, were proposed in the past but they are affected by some straits in deployment. In this paper a Traffic Monitoring Wireless Sensor Network system (TM-WSN), based on acoustic arrays and powered by effective post-processing, is proposed. The system is composed by an hierarchical scheme of Master Nodes and Sensor Nodes linked with a multi-hop protocol. Key features are traffic monitoring and queue detection to be performed in real-time at unprecedented space scale.

Design and application of enhanced communication protocols for wireless sensor networks operating in environmental monitoring

The effective application of Wireless Sensor Networks (WSNs) to wide area environmental monitoring currently represents a challenge for this technology. Since devices are usually energy constrained, smart power saving procedures are needed to increase the network lifetime. A common approach is to switch off the nodes radio; this definitely requires the adoption of synchronisation procedures that properly schedule packets transmission to avoid both overhearing effects and collisions. To this end, a novel class of MAC layer protocols, named STAR MAC, is presented. This is further improved by introducing STAR+ scheme and properly integrating within a routing solution, according to the cross-layer design. It allows the optimisation of energetic consumption, or equivalently, network life-time, together with minimising the signalling overhead. The proposed solution is then applied to a realistic user-defined scenario, highlighting remarkable advantages both in terms of robustness, self reconfigurability, cost, complexity and QoS, thus validating the proposed solution.

Development of Wireless Sensor Networks for Agricultural Monitoring

The concept of precision agriculture has been around for some time now. Blackmore et al., in 1994 [1] defined it as a comprehensive system designed to optimize agricultural production by carefully tailoring soil and crop management to correspond to the unique condition found in each field while maintaining environmental quality. The early adopters during that time found precision agriculture to be unprofitable and the instances in which it was implemented were few and far between. Further, the high initial investment in the form of electronic equipment for sensing and communication meant that only large farms could afford it.