Energy scavenging for long-term deployable wireless sensor networks

Utility companies (electricity, gas, and water suppliers), governments, and researchers have been urging to deploy communication-based systems to read meters, known as automatic meter reading (AMR) An AMR system is envisaged to bring on benefits to customers, utilities, and governments The advantages include reducing peak demand for energy, supporting the time-of-use concept for billing, enabling customers to make informed decisions, and reducing the cost of meter reading, to name a few A key element in an AMR system is communications between meters and utility servers Though several communication technologies have been proposed and implemented at a small scale, with the wide proliferation of wireless communication, it is the right time to critique the old proposals and explore new possibilities for the next generation AMR We provide a comprehensive review of the AMR technologies proposed so far Next, we present how future AMRs will benefit from third generation (3G) communication systems, the DLMS/COSEM (Data Language Messaging Specification/Companion Specification for Energy Metering) standard and Internet Protocol-based SIP (Session Initiation Protocol) signaling at the application level The DLMS/COSEM standard provides a framework for meters to report application data (ie meter readings) to a utility server in a reliable manner The SIP protocol is envisaged to be used as the signaling protocol between application entities running on meters and servers The DLMS/COSEM standard and the SIP protocol are expected to provide an application level communication abstraction to achieve reliability and scalability Finally, we identify the challenges at the application level that need to be tackled The challenges include handling failure, gathering meter data under different time constraints (ranging from real-time to delay-tolerance), disseminating (ie, unicasting, multicasting, broadcasting, and geocasting) control data to the meters, and achieving secure communication

A Survey of Communication Protocols for Automatic Meter Reading Applications

Wireless Sensor Networks (WSNs) represent a very promising solution in the field of wireless technologies for industrial applications. However, for a credible deployment of WSNs in an industrial environment, four main properties need to be fulfilled, i.e., energy efficiency, scalability, reliability, and timeliness. In this paper, we focus on IEEE 802.15.4 WSNs and show that they can suffer from a serious unreliability problem. This problem arises whenever the power management mechanism is enabled for energy efficiency, and results in a very low packet delivery ratio, also when the number of sensor nodes in the network is very low (e.g., 5). We carried out an extensive analysis-based on both simulation and experiments on a real WSN-to investigate the fundamental reasons of this problem, and we found that it is caused by the contention-based Medium Access Control (MAC) protocol used for channel access and its default parameter values. We also found that, with a more appropriate MAC parameters setting, it is possible to mitigate the problem and achieve a delivery ratio up to 100%, at least in the scenarios considered in this paper. However, this improvement in communication reliability is achieved at the cost of an increased latency, which may not be acceptable for industrial applications with stringent timing requirements. In addition, in some cases this is possible only by choosing MAC parameter values formally not allowed by the standard.

/pdf/a-comprehensive-analysis-of-the-mac-unreliability-problem-in-1aalzjf0re.pdf

A Comprehensive Analysis of the MAC Unreliability Problem in IEEE 802.15.4 Wireless Sensor Networks

The increasing complexity of wireless standards has shown that protocols cannot be designed once for all possible deployments, especially when unpredictable and mutating interference situations are present due to the coexistence of heterogeneous technologies. As such, flexibility and (re)programmability of wireless devices is crucial in the emerging scenarios of technology proliferation and unpredictable interference conditions. In this paper, we focus on the possibility to improve coexistence performance of WiFi and ZigBee networks by exploiting novel programmable architectures of wireless devices able to support run-time modifications of medium access operations. Differently from software-defined radio (SDR) platforms, in which every function is programmed from scratch, our programmable architectures are based on a clear decoupling between elementary commands (hard-coded into the devices) and programmable protocol logic (injected into the devices) according to which the commands execution is scheduled. Our contribution is two-fold: first, we designed and implemented a cross-technology time division multiple access (TDMA) scheme devised to provide a global synchronization signal and allocate alternating channel intervals to WiFi and ZigBee programmable nodes; second, we used the OMF control framework to define an interference detection and adaptation strategy that in principle could work in independent and autonomous networks. Experimental results prove the benefits of the envisioned solution.

/pdf/exploiting-programmable-architectures-for-wifi-zigbee-inter-2k0amlb1aq.pdf

Exploiting programmable architectures for WiFi/ZigBee inter-technology cooperation

The IEEE 802.15.4 standard is designed as a low power and low data rate protocol offering high reliability. It defines a beaconed and unbeaconed version. In this work, we analyze the maximum throughput and minimum delay of the unbeaconed or unslotted version of the protocol. First, the most important features are described. Then the exact formula for the throughput and delay of a direct transmission between one sender and one receiver is given. This is done for the different frequency ranges and address structures used in IEEE 802.15.4. The analysis is limited to the unslotted version as this one experiences the lowest overhead. It is shown that the maximum throughput depends on the packet size. In the 2.4 GHz band, a bandwidth efficiency of 64.9% is reached when the maximum packet size is used. Further we describe the influence of the back off interval. A significant gain is found when the backs off parameters are altered. We have measured the throughput experimentally in order to compare the theoretical analysis with real-life examples.

/pdf/throughput-and-delay-analysis-of-unslotted-ieee-802-15-4-14h7dwq5zn.pdf

Throughput and Delay Analysis of Unslotted IEEE 802.15.4

This paper investigates the maximum throughput and minimum delay of the new IEEE 802.15.4-standard. This standard was designed as a highly reliable and low-power protocol working at a low data rate and offers a beaconed and unbeaconed version. We will give the exact formulae for a transmission between one sender and one receiver for the unbeaconed version as this one has the least overhead. Further, the influence of the different address schemes, i.e. no addresses or the use of long and short addresses, is investigated. It is shown that the maximum throughput is not higher than 163 kbps when no addresses are used and that the maximum throughput drops when the other address schemes are used. Finally, we will measure the throughput experimentally in order to validate our theoretical analysis.

Maximum throughput and minimum delay in IEEE 802.15.4

Most wireless sensor networks (WSNs) consist of battery-powered nodes and are limited to hundreds of nodes. Battery replacement is a very costly operation and a key factor in limiting successful large-scale deployments. The recent advances in both energy harvesters and low-power communication systems hold promise for deploying large-scale wireless green-powered sensor networks (WGSNs). This will enable new applications and will eliminate environmentally unfriendly battery disposal. This paper explores the use of energy harvesters to scavenge power for nodes in a WSN. The design and implementation of a generic energy-harvesting framework, suited for a WSN simulator as well as a real-life testbed, are proposed. These frameworks are used to evaluate whether a carrier sense multiple access with collision avoidance scheme is sufficiently reliable for use in emerging large-scale energy harvesting electronic shelf label (EHESL) systems (i.e., 12000 labels in a star topology). Both the simulator and testbed experiments yielded an average success rate up to 92%, with an arrival rate of 40 transceive cycles per second. We have demonstrated that our generic energy-harvesting framework is useful for WGSN research because the simulator allowed us to verify the achieved results on the real-life testbed and vice versa.

https://link.springer.com/content/pdf/10.1155%2F2010%2F343690.pdf

Design and implementation of a generic energy-harvesting framework applied to the evaluation of a large-scale electronic shelf-labeling wireless sensor network

Demo abstract: WiLab, a real-life wireless sensor testbed with environment emulation

Wireless Building Automation is a complex problem dealing with a lot of trade offs: on one hand sensors and actuators have to be as energy-efficient as possible, while on the other hand the overall network should be performant and resilient enough to extend or even replace a wired backbone. In addition, the network should be able to serve existing IEEE 802.11 devices such as PDAs, cameras and laptops. Furthermore, surveillance, fire detection and other critical building automation applications require end-to-end Quality of Service support to ensure the bandwidth and delay requirements also in the case of high network loads. A networking technology that simultaneously fulfills all those requirements does not exist. This paper introduces a system architecture that combines heterogeneous technologies into an appropriate networking solution.

https://biblio.ugent.be/publication/423704/file/448574.PDF

Pieter De Mil

Papers

Throughput and Delay Analysis of Unslotted IEEE 802.15.4

Maximum throughput and minimum delay in IEEE 802.15.4

Design and implementation of a generic energy-harvesting framework applied to the evaluation of a large-scale electronic shelf-labeling wireless sensor network

Demo abstract: WiLab, a real-life wireless sensor testbed with environment emulation

A system architecture for wireless building automation