Wireless sensors networks

After studying in depth look at wireless sensor networks are quite clear improvement compared to traditional wireless networks due to several factors as are the durability of the lifetime of the batteries, allowing greater portability of sensor nodes and that can record more events to power stay longer in some places, the routing protocols networks sensors allow gain than in durability also gain in efficiency the avoidance of collisions between packets, which also ensures a lower number of unnecessary network traffic. Because of the great features of such networks are currently using sensor networks in many projects related to different fields such as: environment, health, military, construction and structures, automotive, home automation, agriculture, etc. This type of network currently is leading a technological revolution similar to that had appearance of internet, because the applications appear to be infinite, also speaks global surveillance network on the planet capable of recording and tracking people specific goods and research projects have generated great interest for application in practice

Initialization algorithms for wireless ad-hoc networks

The aim of this master thesis is the implementation of simulation models and the simulation of energy-efficient network initialization algorithms. First of all, it is presented a survey of state-of-the-art strategies for network initialization and exploration in wireless ad-hoc networks. Among the routing approaches presented in the survey it has been chosen the clustering-based approach due to it is the most suitable for ad-hoc sensor networks. Following are explained the features and properties of the clustering-based routing algorithms that have been selected for their implementation on this work. These implemented routing protocols are LEACH, LEACH-C, the solaraware extensions of both, HEED and a protocol based on direct transmission just as a reference in the comparison among the rest of them. On the other hand, all these routing protocols have been implemented and simulated using the OMNeT++ 4.0, which is a freeware discrete simulation environment. Subsequently, all the protocols have been simulated with different parameters and conditions to prove their functionality and to find out their behaviour in different sorts of sensor networks. Next, the simulations of the algorithms are compared among each other especially in terms of communication and energy efficiency. There are presented different comparisons such as LEACH and LEACH-C with their respective solar-aware extensions of both, a comparison between HEED with optimized parameters and non-optimized parameters, and finally a general comparison among One-hop, LEACH, LEACH-C and HEED. To sum up, some conclusions are drawn about the performance of the different protocols and some key points are given for future work. Furthermore, it is presented a brief study of the environmental impact this work may have

Evaluation of Wireless Sensor Networks Technologies

Wireless sensor networks represent a new technology that has emerged from developments in ultra low power microcontrollers and sophisticated low cost wireless data devices. Their small size and power consumption allow a number of independent ‘nodes’ (known as Motes) to be distributed in the field, all capable of ad-hoc networking and multihop message transmission. New routing algorithms allow remote data to be passed reliably through the network to a final control point. This occurs within the constraints of low power RF transmissions in a congested 2.4GHz radio spectrum. Wireless sensor network nodes are suitable for applications requiring long term autonomous operation, away from mains power supplies, such as environmental or health monitoring. To achieve this, sophisticated power management techniques must be used, with the units remaining ‘asleep’ in ultra low power mode for long periods of time. The main aim of this research described in this thesis is first to review the area and then to evaluate one of the current hardware platforms and the popular software used with it called TinyOS. Therefore this research uses a hardware platform designed from University of Berkeley, called the TmoteSky. Practical work has been carried out in different scenarios. Using Java tools running on a PC, and customized applications running on the Motes, data has been captured, together with information showing topology configuration and adaptive routing of the network and radio link quality information. Results show that the technology is promising for distributed data acquisition applications, although in time critical monitoring systems new power management schemes and networking protocols to improve latency in the system will be required

On-Site and External Energy Harvesting in Underground Wireless

Energy efficiency is vital for uninterrupted long-term operation of wireless underground communication nodes in the field of decision agriculture. In this paper, energy harvesting and wireless power transfer techniques are discussed with applications in underground wireless communications (UWC). Various external wireless power transfer techniques are explored. Moreover, key energy harvesting technologies are presented that utilize available energy sources in the field such as vibration, solar, and wind. In this regard, the Electromagnetic(EM)- and Magnetic Induction(MI)-based approaches are explained. Furthermore, the vibration-based energy harvesting models are reviewed as well. These energy harvesting approaches lead to design of an efficient wireless underground communication system to power underground nodes for prolonged field operation in decision agriculture

The EcoThermo project: key and innovative aspects

In this paper we present the most innovative aspects of the EC-FP7 EcoThermo project. The main aim of the project consists on innovating the technique of heat cost allocation in buildings with a centralized heating system, overcoming the heat cost allocator drawbacks for reliability, measurement reproducibility and traceability and contexts of applications. Given the complexity of the project, we will focus on its main aspects, such as the use of a virtual sensor to estimate the radiators heating power, the design of electronic valves fitted out with an energy harvesting system and the original wireless communication protocol

Performance analysis and application development of hybrid WiMAX-WiFi IP video surveillance systems

Traditional Closed Circuit Television (CCTV) analogue cameras installed in buildings and other areas of security interest necessitates the use of cable lines. However, analogue systems are limited by distance; and storing analogue data requires huge space or bandwidth. Wired systems are also prone to vandalism, they cannot be installed in a hostile terrain and in heritage sites, where cabling would distort original design. Currently, there is a paradigm shift towards wireless solutions (WiMAX, Wi-Fi, 3G, 4G) to complement and in some cases replace the wired system. A wireless solution of the Fourth-Generation Surveillance System (4GSS) has been proposed in this thesis. It is a hybrid WiMAX-WiFi video surveillance system. The performance analysis of the hybrid WiMAX-WiFi is compared with the conventional WiMAX surveillance models. The video surveillance models and the algorithm that exploit the advantages of both WiMAX and Wi-Fi for scenarios of fixed and mobile wireless cameras have been proposed, simulated and compared with the mathematical/analytical models. The hybrid WiMAX-WiFi video surveillance model has been extended to include a Wireless Mesh configuration on the Wi-Fi part, to improve the scalability and reliability. A performance analysis for hybrid WiMAX-WiFi system with an appropriate Mobility model has been considered for the case of mobile cameras. A security software application for mobile smartphones that sends surveillance images to either local or remote servers has been developed. The developed software has been tested, evaluated and deployed in low bandwidth Wi-Fi wireless network environments. WiMAX is a wireless metropolitan access network technology that provides broadband services to the connected customers. Major modules and units of WiMAX include the Customer Provided Equipment (CPE), the Access Service Network (ASN) which consist one or more Base Stations (BS) and the Connectivity Service Network (CSN). Various interfaces exist between each unit and module. WiMAX is based on the IEEE 802.16 family of standards. Wi-Fi, on the other hand, is a wireless access network operating in the local area network; and it is based on the IEEE 802.11 standards

Modeling of On-line Traffic Control and Management Network for Operational and Communication Performance Evaluation

Communication systems are the backbone of every effective and reliable traffic control and management application. While traditional fiber optics and telephone communications have long been used in managing and controlling highway traffic, wireless communication technology shows great promise as an alternative solution in traffic management applications due to their suitability for deployment in rural areas, and their flexibility and cost-effectiveness for system expansion. However, the detailed characteristics of various wireless communication technologies and real performance in the field have not been systematically studied. To augment this existing knowledge so that traffic professionals may better utilize these technologies to improve traffic safety, mobility and efficiency, this study aims to 1) identify existing wireless communication technologies used in ITS, and potential wireless communication alternatives that can be widely used in ITS, 2) evaluate the performance, cost and reliability of existing and potential wireless communication technologies in supporting on-line traffic control and management functions, and 3) apply benefit-cost analysis to identify the impacts of using these wireless technologies to support on-line traffic management. To achieve these research objectives, the author first conducted an interview to discover the specifications of existing communication infrastructures deployed for various ITS related applications and the usage of wireless technologies in different states. Moreover, the author proposed a network design process that considered wireless coverage range and network topology, followed with case studies utilizing Wireless Fidelity (WiFi) and Worldwide Interoperability for Microwave Access (WiMAX) technologies to support a traffic surveillance system in seven metropolitan areas throughout South Carolina. Field tests were conducted to evaluate the performance and reliability of wireless transmissions between adjacent sensor nodes. After that, the author applied a communication simulator, ns-2, to compare the communication performance of a traffic sensor network with WiFi and WiMAX technologies under infrastructure and mesh topologies, and environmental conditions. Based on these simulation results, the author conducted performance-cost analysis for these selected technologies and topologies. The WiFi field test results indicated that wireless communication performance between two traffic sensors significantly degrades after 300 ft; this distance, however, may vary with the modulation rates and transmission power upon which the system operates. WiMAX nomadic test suggested that line-of-sight (LOS) greatly affects the connectivity level. Moreover, the capabilities and the performance of the WiMAX network are sometimes affected by the characteristics of the client radio. The simulation analysis and benefit-cost analysis indicated a WiFi mesh network solution has the highest throughput-cost ratio, 109 bits/dollar for supporting traffic surveillance systems, while the WiMAX infrastructure option provides the greatest amount of excess bandwidth, 9.15Mbps per device, which benefits the system\u27s future expansion. This dissertation provides an important foundation for further investigation of the performance and reliability of different wireless technologies. In addition, research results presented in this dissertation will benefit transportation agencies and other stakeholders in evaluating and selecting wireless communication options for different traffic control and management applications

The EcoThermo project: key and innovative aspects

In this paper we present the most innovative aspects of the EC-FP7 EcoThermo project. The main aim of the project consists on innovating the technique of heat cost allocation in buildings with a centralized heating system, overcoming the heat cost allocator drawbacks for reliability, measurement reproducibility and traceability and contexts of applications. Given the complexity of the project, we will focus on its main aspects, such as the use of a virtual sensor to estimate the radiators heating power, the design of electronic valves fitted out with an energy harvesting system and the original wireless communication protocol