Browsing by Subject "Wireless sensor networks"

Now showing 1 - 6 of 6
  • Thumbnail Image
    Item
    Average Consensus in Wireless Sensor Networks with Probabilistic Network Links
    (2010) Saed, Steve; Li, Lingxi; Kim, Dongsoo S.; King, Brian
    This study proposes and evaluates an average consensus scheme for wireless sensor networks. For this purpose, two communication error models, the fading signal error model and approximated fading signal error model, are introduced and incorporated into the proposed decentralized average consensus scheme. Also, a mathematical analysis is introduced to derive the approximated fading signal model from the fading signal model. Finally, differnt simulation scenarios are introduced and their results analyzed to evaluate the performance of the proposed scheme and its effectiveness in meeting the needs of wireless sensor networks.
  • Thumbnail Image
    Item
    A Compressed Data Collection System For Use In Wireless Sensor Networks
    (2013-03-06) Erratt, Newlyn S.; Liang, Yao; Raje, Rajeev; Tuceryan, Mihran
    One of the most common goals of a wireless sensor network is to collect sensor data. The goal of this thesis is to provide an easy to use and energy-e fficient system for deploying data collection sensor networks. There are numerous challenges associated with deploying a wireless sensor network for collection of sensor data; among these challenges are reducing energy consumption and the fact that users interested in collecting data may not be familiar with software design. This thesis presents a complete system, comprised of the Compression Data-stream Protocol and a general gateway for data collection in wireless sensor networks, which attempts to provide an easy to use, energy efficient and complete system for data collection in sensor networks. The Compressed Data-stream Protocol is a transport layer compression protocol with a primary goal, in this work, to reduce energy consumption. Energy consumption of the radio in wireless sensor network nodes is expensive and the Com-pressed Data-stream Protocol has been shown in simulations to reduce energy used on transmission and reception by around 26%. The general gateway has been designed in such a way as to make customization simple without requiring vast knowledge of sensor networks and software development. This, along with the modular nature of the Compressed Data-stream Protocol, enables the creation of an easy to deploy and easy to configure sensor network for data collection. Findings show that individual components work well and that the system as a whole performs without errors. This system, the components of which will eventually be released as open source, provides a platform for researchers purely interested in the data gathered to deploy a sensor network without being restricted to specific vendors of hardware.
  • Thumbnail Image
    Item
    Context-Aware Collaborative Intelligence With Spatio-Temporal In-Sensor-Analytics for Efficient Communication in a Large-Area IoT Testbed
    (IEEE, 2021) Chatterjee, Baibhab; Seo, Dong-Hyun; Chakraborty, Shramana; Avlani, Shitij; Jiang, Xiaofan; Zhang, Heng; Abdallah, Mustafa; Raghunathan, Nithin; Mousoulis, Charilaos; Shakouri, Ali; Bagchi, Saurabh; Peroulis, Dimitrios; Sen, Shreyas; Electrical and Computer Engineering, Purdue School of Engineering and Technology
    Decades of continuous scaling has reduced the energy of unit computing to virtually zero, while energy-efficient communication has remained the primary bottleneck in achieving fully energy-autonomous Internet-of-Things (IoT) nodes. This article presents and analyzes the tradeoffs between the energies required for communication and computation in a wireless sensor network, deployed in a mesh architecture over a 2400-acre university campus, and is targeted toward multisensor measurement of temperature, humidity and water nitrate concentration for smart agriculture. Several scenarios involving in-sensor analytics (ISA), collaborative intelligence (CI), and context-aware switching (CAS) of the cluster head during CI has been considered. A real-time co-optimization algorithm has been developed for minimizing the energy consumption in the network, hence maximizing the overall battery lifetime. Measurement results show that the proposed ISA consumes ≈ 467× lower energy as compared to traditional Bluetooth low energy (BLE) communication, and ≈ 69500× lower energy as compared with long-range (LoRa) communication. When the ISA is implemented in conjunction with LoRa, the lifetime of the node increases from a mere 4.3 h to 66.6 days with a 230-mAh coin cell battery, while preserving >99% of the total information. The CI and CAS algorithms help in extending the worst case node lifetime by an additional 50%, thereby exhibiting an overall network lifetime of ≈ 104 days, which is >90% of the theoretical limits as posed by the leakage current present in the system, while effectively transferring information sampled every second. A Web-based monitoring system was developed to continuously archive the measured data, and for reporting real-time anomalies.
  • Thumbnail Image
    Item
    Embedded System for Sensor Communication and Security
    (2010) An, Feng; Rizkalla, Maher; Li, Lingxi; Du, Yingzi; Salama, Paul; Knieser, Michael
    In this work, inter-integrated circuit mode (I2C) software was used to communicate between sensors and the embedded control system, utilizing PIC182585 MPLAB hardware. These sensors were built as part of a system on board that includes the sensors, microcontroller, and interface circuitry. The hardware includes the PIC18 processor, FPGA chip, and peripherals. A FPGA chip was used to interface the processor with the peripherals in order to operate at the same clock speed. This hardware design features high level of integration, reliability, high precision, and high speed communications. The software was first designed to operate each sensor separately, then the sensor system was integrated (to combine all sensors, microcontroller, and interfacing circuitries), and the software was updated to provide various actions if triggered by the sensors. Actions taken by the processor may include alarming signals that are based on threshold values received from the sensors, and inquiring temperature and CO2 readings. The system was designed for HVAC (heating, ventilating and air conditioning) applications and industrial settings. The overall system incorporating temperature and CO2 sensors was implemented and successfully tested. The response of the multi-sensor system was agreeable with the design parameters. The system may be expanded to include other sensors such as light senor, pressure sensor, etc. Monitoring the threshold values should add to the security features of the integrated communication system. This design features low power consumption (utilizing the sleeping mode of the processors), high speed communications, security, and flexibility to expansion.
  • Thumbnail Image
    Item
    Energy-efficient and balanced routing in low-power wireless sensor networks for data collection
    (Elsevier, 2022-03) Navarro, Miguel; Liang, Yao; Zhong, Xiaoyang; Computer and Information Science, School of Science
    Cost-based routing protocols are the main approach used in practical wireless sensor network (WSN) and Internet of Things (IoT) deployments for data collection applications with energy constraints; however, those routing protocols lead to the concentration of most of the data traffic on some specific nodes which provide the best available routes, thus significantly increasing their energy consumption. Consequently, nodes providing the best routes are potentially the first ones to deplete their batteries and stop working. In this paper, we introduce a novel routing strategy for energy efficient and balanced data collection in WSNs/IoT, which can be applied to any cost-based routing solution to exploit suboptimal network routing alternatives based on the parent set concept. While still taking advantage of the stable routing topologies built in cost-based routing protocols, our approach adds a random component into the process of packet forwarding to achieve a better network lifetime in WSNs. We evaluate the implementation of our approach against other state-of-the-art WSN routing protocols through thorough real-world testbed experiments and simulations, and demonstrate that our approach achieves a significant reduction in the energy consumption of the routing layer in the busiest nodes ranging from 11% to 59%, while maintaining over 99% reliability. Furthermore, we conduct the field deployment of our approach in a heterogeneous WSN for environmental monitoring in a forest area, report the experimental results and illustrate the effectiveness of our approach in detail. Our EER based routing protocol CTP+EER is made available as open source to the community for evaluation and adoption.
  • Thumbnail Image
    Item
    SCALABLE AND QoS NETWORKING SOLUTIONS FOR TELEMEDICINE
    (2011-03-09) Payli, Birhan; Durresi, Arjan; Tuceryan, Mihran; Xia, Yuni
    Retrieving data from a patient in real-time is a challenging operation, especially when requiring information from the network to support the patient’s health. A real-time healthcare system process is conducted with a continual input, processing, and output of data. It needs to have the ability to provide different priorities to different applications, users, or data flows, or to guarantee a certain level of performance to a data flow. The current Internet does not allow applications to request any special treatment. Every packet, including delay-sensitive audio and video packets, is treated equally at the routers. This simplest type service of network is often referred to as best effort, a network service in which the network does not provide any guarantees that data is delivered or that a user is given a guaranteed QoS level or a certain priority. Providing guaranteed services requires routers to manage per-flow states and perform per-flow operations. Such network architecture requires each router to maintain and manage perflow state on the control path, and to perform per-flow classification, scheduling, and buffer management on the data path. This complicated and expensive network architecture is less scalable and robust than today’s modern stateless network architectures such as Random Early Dropping (RED) for congestion control, DiffServ for QoS, and the original IP network. This thesis introduces a new DiffServ-based scheme of IP bandwidth allocation during congestion, called Proportional Allocation of Bandwidth (PAB) which can be used in all networks. In PAB scheme, the bandwidth is allocated in proportion to Subscripted Information Rate (SIR) of the competing flows. PAB implementation uses multiple token buckets to label the packets at the edge of the network and multilevel threshold queue at the IP routers to discard packets during congestion.