Ultra-low Power Wireless Sensor Network Research Articles

Ultra-Low Power Wireless Sensor Networks Based on Time Slotted Channel Hopping with Probabilistic Blacklisting

Devices in wireless sensor networks are typically powered by batteries, which must last as long as possible to reduce both the total cost of ownership and potentially pollutant wastes when disposed of. By lowering the duty cycle to the bare minimum, time slotted channel hopping manages to achieve very low power consumption, which makes it a very interesting option for saving energy, e.g., at the perception layer of the Internet of Things. In this paper, a mechanism based on probabilistic blacklisting is proposed for such networks, which permits to lower power consumption further. In particular, channels suffering from non-negligible disturbance may be skipped based on the perceived quality of communication so as to increase reliability and decrease the likelihood that retransmissions have to be performed. The only downside of this approach is that the transmission latency may grow, but this is mostly irrelevant for systems where the sampling rates are low enough.

A Fully Integrated Programmable 6.0–8.5-GHz UWB IR Transmitter Front-End for Energy-Harvesting Devices

Ultra-wideband impulse radio transceivers are becoming a key building block for establishing ultralow power wireless sensor networks. However, impulse radio transmitters commonly suffer from a low spectral quality and a coarse frequency tuning resolution, which limits their global applicability. In this article, we present a fully integrated ultralow power impulse radio transmitter front-end (TFE) whose pulse shaping capabilities and integrated output matching network make it globally applicable up to a 4-MHz pulse repetition rate. We demonstrate a digital carrier frequency-tuning method that achieves a 28-MHz resolution over the frequency band of 6.0–8.5 GHz. In addition, we show that the temperature dependence of the TFE’s carrier frequency can be compensated digitally over the industrial temperature range from −40°C to 85 °C. The proposed TFE supports energy-harvesting applications particularly well due to its low leakage power level of 380 nW and a high tolerance to power supply transients during pulse generation. It is demonstrated to operate robustly with low-drive regulators powered by low-quality sources. The TFE is fabricated in a 65-nm CMOS process. It generates 1.8-pJ pulses at a 7.5-GHz carrier frequency while consuming 63 pJ per pulse, corresponding to 2.3% efficiency.

A System-Level Methodology for the Design of Reliable Low-Power Wireless Sensor Networks.

Innovative Internet of Things (IoT) applications with strict performance and energy consumption requirements and where the agile collection of data is paramount are arising. Wireless sensor networks (WSNs) represent a promising solution as they can be easily deployed to sense, process, and forward data. The large number of Sensor Nodes (SNs) composing a WSN are expected to be autonomous, with a node’s lifetime dictated by the battery’s size. As the form factor of the SN is critical in various use cases, minimizing energy consumption while ensuring availability becomes a priority. Moreover, energy harvesting techniques are increasingly considered as a viable solution for building an entirely green SN and prolonging its lifetime. In the process of building a SN and in the absence of a clear and well-rounded methodology, the designer can easily make unfounded and suboptimal decisions about the right hardware components, their configuration, and reliable data communication techniques, such as automatic repeat request (ARQ) and forward error correction (FEC). In this paper, a methodology to design, configure, and deploy a reliable ultra-low power WSNs is proposed. A comprehensive energy model and a realistic path-loss (PL) model of the sensor node are also established. Through estimations and field measurements it is proven that, following the proposed methodology, the designer can thoroughly explore the design space and the make most favorable decisions when choosing commercial off-the-shelf (COTS) components, configuring the node, and deploying a reliable and energy-efficient WSN.

BATS: Adaptive Ultra Low Power Sensor Network for Animal Tracking.

In this paper, the BATS project is presented, which aims to track the behavior of bats via an ultra-low power wireless sensor network. An overview about the whole project and its parts like sensor node design, tracking grid and software infrastructure is given and the evaluation of the project is shown. The BATS project includes a lightweight sensor node that is attached to bats and combines multiple features. Communication among sensor nodes allows tracking of bat encounters. Flight trajectories of individual tagged bats can be recorded at high spatial and temporal resolution by a ground node grid. To increase the communication range, the BATS project implemented a long-range telemetry system to still receive sensor data outside the standard ground node network. The whole system is designed with the common goal of ultra-low energy consumption while still maintaining optimal measurement results. To this end, the system is designed in a flexible way and is able to adapt its functionality according to the current situation. In this way, it uses the energy available on the sensor node as efficient as possible.

Design and demonstration of a wireless sensor network platform for substation asset management

A key challenge for distribution and transmission system operators is to relate the retrofitting of monitoring systems to support asset management aligned with the continuity of service within the electrical network. The research within this study demonstrates how a Smart System Integration approach, utilising a wireless sensor network (WSN), can provide a low cost and scalable sensor platform for in situ sensing of SF6 within substations. In this study, the design and manufacturing stages of an ultra-low power WSN are outlined. The WSN is evaluated within a high-voltage laboratory and deployed within a 400 kV substation. Results indicated that the system can reliably transmit data within a noise environment, recover when there is a mote failure without data loss, can operate on batteries for 1.5 years or 5 years taking 1 SF6 density measurement every 60 or 300 s, respectively. The findings of this research demonstrated the advantageous features of WSNs, namely low cost, rapid deployment, reliable and secure data transfer, adaptive and scalable sensor platform.

Enerji verimli ve düşük maliyetli sensör ağlarının ISM bandı FSK alıcı vericiyle tasarlanması

Safe wireless link and long battery life are indispensable feature for a portable and outdoor used device with build-in sensors. For this purpose, duty cycling, ultra-low power electronics design, dynamic power management, wireless network architecture and medium access control concepts in the design are explained in detailed.  In this work, an ultra-low power wireless sensor network is designed with 4cmx4cm size and light weight nodes sending once every three minutes 115.2 kbps 5 byte package that have up to 131.25 year battery life time in theory with 3V (2x1.5V) 1000mAh battery. 868 and 915 MHz programmable 115.2 kbps ISM band FSK RF transceiver with a low power wake-up scheme is utilized for low cost unlicensed-used wireless sensor networks designed with Back Inverted F Antennas with 100m communication range for outdoor applications and 25m for indoor applications. Sensor node requires 0.5 uA, 2.5 mA, 0.8 uA, 14.6 mA and 25mA during sleep, measurement, sniff, receive and transmit mode respectively @ 868 MHz with 3V battery. The sensors has temperature compensation feature with -40-85 °C working range.

RoSe: A Subgigahertz Wireless Sensor Platform With Housing-Integrated Overmolded Antenna

A wireless sensor platform for use in ultralow-power wireless sensor networks (WSNs) is presented. The proposed round sensor (RoSe) node is physically robust, is resistant to humidity, and has a housing that can be in direct contact with food. These characteristics are achieved via injection molding technology which is investigated at both the component and the system levels. The results of injection molding tests on the node's electronic components are reported, while a housing-integrated overmolded antenna is conceived and realized. The radiator, operating in the subgigahertz industrial, scientific, and medical (ISM) band (ISM 868 or 915 MHz), has been characterized, and a good correspondence with theoretical predictions is observed. The proposed system enables industrialized mass production and results in a generic platform for wireless monitoring applications. In this paper, we present the RoSe node with a temperature sensor for use in food cold chain management, i.e., for use at temperatures down to -30 °C and in frequent contact with water due to condensation or cleaning. Its ultralow-power characteristics are demonstrated by the analysis of the charge consumption when the node performs specific tasks both in a test case and operating in a WSN. Long-term battery lifetime results while running a demo WSN are also presented.

Positioning in Synchronized Ultra Low-Power Wireless Sensor Networks

Wireless Sensor Networks (WSNs) consist of densely deployed, independent, and collaborating low cost sensor nodes. The nodes are highly resource-constrained in terms of energy, processing, and data storage capacity. Thus, the protocols used in WSNs must be highly energy-efficient. WSN communication protocols achieving the lowest power consumption minimize radio usage by accurately synchronizing transmissions and receptions with their neighbors. In this paper, we show how network signaling frames of state-of-the-art synchronized communication protocols for low-power WSNs supporting mobile nodes can be used for positioning. We derive mathematical models for node power consumption analysis. Both centralized and distributed positioning architectures are modeled. The models provide a tool for estimating what kind of network lifetimes can be expected when average positioned node speed, the amount of anchor nodes required by the location estimation algorithm, and the location refresh rate required by the application are known. The presented analysis results are based on two kinds of node hardware: with and without Received Signal Strength Indicator (RSSI). The results show that the positioning parameters and used hardware have significant impact on node power consumption and network lifetime. In the presented results, the network lifetime ranges from over 10 years to 2 months with different positioning requirements and hardware. keywords: Wireless, Low-Power, Sensor Networks c ⃝[2010] IEEE. Portions reprinted, with permission, from [Ville Kaseva, Timo D. Hamalainen, and Marko Hannikainen, Positioning in Resource-Constrained Ultra Low-Power Wireless Sensor Networks, Ubiquitous Positioning Indoor Navigation and Location Based Service (UPINLBS), October/2010]