Appearing in 1st IEEE International Workshop on Sensor Net Protocols and Applications (SNPA). Anchorage, Alaska, USA. May 11, 2003. RMST: Reliable Data Transport in Sensor Networks Fred Stann, John Heidemann Abstract – Reliable data transport in wireless sensor networks is a multifaceted problem influenced by the physical, MAC, network, and transport layers. Because sensor networks are subject to strict resource constraints and are deployed by single organizations, they encourage revisiting traditional layering and are less bound by standardized placement of services such as reliability. This paper presents analysis and experiments resulting in specific recommendations for implementing reliable data transport in sensor nets. To explore reliability at the transport layer, we present RMST (Reliable Multi- Segment Transport), a new transport layer for Directed Diffusion. RMST provides guaranteed delivery and fragmentation/reassembly for applications that require them. RMST is a selective NACK-based protocol that can be configured for in-network caching and repair. Second, these energy constraints, plus relatively low wireless bandwidths, make in-network processing both feasible and desirable [3]. Third, because nodes in sensor networks are usually collaborating towards a common task, rather than representing independent users, optimization of the shared network focuses on throughput rather than fairness. Finally, because sensor networks are often deployed by a single organization with inexpensive hardware, there is less need for interoperability with existing standards. For all of these reasons, sensor networks provide an environment that encourages rethinking the structure of traditional communications protocols. The main contribution is an evaluation of the placement of reliability for data transport at different levels of the protocol stack. We consider implementing reliability in the MAC, transport layer, application, and combinations of these. We conclude that reliability is important at the MAC layer and the transport layer. MAC-level reliability is important not just to provide hop-by-hop error recovery for the transport layer, but also because it is needed for route discovery and maintenance. (This conclusion differs from previous studies in reliability for sensor nets that did not simulate routing. [4]) Second, we have developed RMST (Reliable Multi-Segment Transport), a new transport layer, in order to understand the role of in- network processing for reliable data transfer. RMST benefits from diffusion routing, adding minimal additional control traffic. RMST guarantees delivery, even when multiple hops exhibit very high error rates. 1 Introduction Wireless sensor networks provide an economical, fully distributed, sensing and computing solution for environments where conventional networks are impractical. This paper explores the design decisions related to providing reliable data transport in sensor nets. The reliable data transport problem in sensor nets is multi-faceted. The emphasis on energy conservation in sensor nets implies that poor paths should not be artificially bolstered via mechanisms such as MAC layer ARQ during route discovery and path selection [1]. Path maintenance, on the other hand, benefits from well- engineered recovery either at the MAC layer or the transport layer, or both. Recovery should not be costly however, since many applications in sensor nets are impervious to occasional packet loss, relying on the regular delivery of coarse-grained event descriptions. Other applications require loss detection and repair. These aspects of reliable data transport include the provision of guaranteed delivery and fragmentation/ reassembly of data entities larger than the network MTU. Sensor networks have different constraints than traditional wired nets. First, energy constraints are paramount in sensor networks since nodes can often not be recharged, so any wasted energy shortens their useful lifetime [2]. This work was supported by DARPA under grant DABT63-99-1-0011 as part of the SCAADS project, and was also made possible in part due to support from Intel Corporation and Xerox Corporation. Fred Stann and John Heidemann are with USC/Information Sciences Institute, 4676 Admiralty Way, Marina Del Rey, CA, USA E-mail: fstann@usc.edu, johnh@isi.edu. 2 Architectural Choices There are a number of key areas to consider when engineering reliability for sensor nets. Many current sensor networks exhibit high loss rates compared to wired networks (2% to 30% to immediate neighbors)[1,5,6]. While error detection and correction at the physical layer are important, approaches at the MAC layer and higher adapt well to the very wide range of loss rates seen in sensor networks and are the focus of this paper. MAC layer protocols can ameliorate PHY layer unreliability, and transport layers can guarantee delivery. An important question for this paper is the trade off between implementation of reliability at the MAC layer (i.e. hop to hop) vs. the Transport layer, which has traditionally been concerned with end-to-end reliability. Because sensor net applications are distributed, we also considered implementing reliability at the application layer. Our goal is to minimize the cost of repair in terms of transmission.

RMST: Reliable Data Transport in Sensor Networks

While the Internet of Things (IoT) is driving a transformation of current society toward a smarter one, new challenges and opportunities have arisen to accommodate the demands of IoT development. Low power wireless devices are, undoubtedly, the most viable solution for diverse IoT use cases. Among such devices, Bluetooth low energy (BLE) beacons have emerged as one of the most promising due to the ubiquity of Bluetooth-compatible devices, such as iPhones and Android smartphones. However, for BLE beacons to continue penetrating the IoT ecosystem in a holistic manner, interdisciplinary research is needed to ensure seamless integration. This paper consolidates the information on the state-of-the-art BLE beacon, from its application and deployment cases, hardware requirements, and casing design to its software and protocol design, and it delivers a timely review of the related research challenges. In particular, the BLE beacon’s cutting-edge applications, the interoperability between packet profiles, the reliability of its signal detection and distance estimation methods, the sustainability of its low energy, and its deployment constraints are discussed to identify research opportunities and directions.

BLE Beacons for Internet of Things Applications: Survey, Challenges, and Opportunities

The present electric power system structure has lasted for decades; it is still partially proprietary, energy-inefficient, physically and virtually (or cyber) insecure, as well as prone to power transmission congestion and consequent failures. Recent efforts in building a smart grid system have focused on addressing the problems of global warming effects, rising energy-hungry demands, and risks of peak loads. One of the major goals of the new system is to effectively regulate energy usage by utilizing the backbone of the prospectively deployed Automatic Meter Reading (AMR), Advanced Meter Infrastructure (AMI), and Demand Response (DR) programs via the advanced distribution automation and dynamic pricing models. The function of the power grid is no longer a system that only supplies energy to end users, but also allows consumers to contribute their clean energy back to the grid in the future. In the meantime, communications networks in the electric power infrastructure enact critical roles. Intelligent automation proposed in smart grid projects include the Supervisory Control And Data Acquisition/Energy Management Systems (SCADA/EMS) and Phasor Management Units (PMU) in transmission networks, as well as the AMR/AMI associated with field/neighborhood area networks (FAN/NAN) and home area networks (HAN) at the distribution and end-use levels. This article provides an overview of the essentials of the progressive smart grid paradigm and integration of different communications technologies for the legacy power system. Additionally, foreseeable issues and challenges in designing communications networks for the smart grid system are also rigorously deliberated in this paper.

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The Progressive Smart Grid System from Both Power and Communications Aspects

The recent worldwide measures for energy savings call for a larger awareness of the household energy consumption, given the relevant contribution of domestic load to the national energy balance. On the other hand, electricity smart meters together with gas, heat, and water meters can be interconnected in a large network offering a potential value to implement energy savings and other energy-related services, as long as an efficient interface with the final user is implemented. Unfortunately, so far, the interface of such devices is mostly designed and addressed at the utilities supervising the system, giving them relevant advantages, while the communication with the household is often underestimated. This paper addresses this topic by proposing the definition of a local interface for smart meters, by looking at the actual European Union and international regulations, at the technological solutions available on the market, and at those implemented in different countries, and, finally, by proposing specific architectures for a proper consumer-oriented implementation of a smart meter network.

Electricity Smart Meters Interfacing the Households

This review presents the state of the art of the application of energy harvesting in commercial and residential buildings. Electromagnetic (optical and radio frequency), kinetic, thermal and airflow-based energy sources are identified as potential energy sources within buildings and the available energy is measured in a range of buildings. Suitable energy harvesters are discussed and the available and the potential harvested energy calculated. Calculations based on these measurements, and the technical specifications of state-of-the-art harvesters, show that typical harvested powers are: (1) indoor solar cell (active area of 9 cm2, volume of 2.88 cm3): ~300 µW from a light intensity of 1000 lx; (2) thermoelectric harvester (volume of 1.4 cm3): 6 mW from a thermal gradient of 25 °C; (3) periodic kinetic energy harvester (volume of 0.15 cm3): 2 µW from a vibration acceleration of 0.25 m s−2 at 45 Hz; (4) electromagnetic wave harvester (13 cm antenna length and conversion efficiency of 0.7): 1 µW with an RF source power of −25 dBm; and (5) airflow harvester (wind turbine blade of 6 cm diameter and generator efficiency of 0.41): 140 mW from an airflow of 8 m s−1. These results highlight the high potential of energy harvesting technology in buildings and the relative attractions of various harvester technologies. The harvested power could either be used to replace batteries or to prolong the life of rechargeable batteries for low-power (~1 mW) electronic devices.

http://iopscience.iop.org/article/10.1088/0957-0233/25/1/012002/pdf

Review of the application of energy harvesting in buildings

In recent years, the home environment has seen a rapid introduction of network enabled digital technology. This technology offers new and exciting opportunities to increase the connectivity of devices within the home for the purpose of home automation. Moreover, with the rapid expansion of the Internet, there is the added potential for the remote control and monitoring of such network enabled devices. However, the adoption of home automation systems has been slow. This paper identifies the reasons for this slow adoption and evaluates the potential of ZigBee for addressing these problems through the design and implementation of a flexible home automation architecture. A ZigBee based home automation system and Wi-Fi network are integrated through a common home gateway. The home gateway provides network interoperability, a simple and flexible user interface, and remote access to the system. A dedicated virtual home is implemented to cater for the system's security and safety needs. To demonstrate the feasibility and effectiveness of the proposed system, four devices, a light switch, radiator valve, safety sensor and ZigBee remote control have been developed and evaluated with the home automation system.

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A zigbee-based home automation system

Intelligent home environments are one of the major application areas of pervasive computing. Safety and security are two most important issues in the remote monitoring and control of intelligent home environments. This article takes safety and security into consideration together and proposes a phone-out-only policy for ensuring security and virtual home environments for safety. A remote monitoring and control system for a security camera is used to illustrate the new methodologies for safety and security. By using the demonstration system people are able to easily monitor and control a security camera, central heating, microwave oven and washer from anywhere by using mobile phones. Our system distinguishes from the existing DTI (Department of Trade and Industry in the UK) next wave technologies and a few of on-going EU projects in the ways of dealing with safety and security and its simplicity. Remote monitoring and control of intelligent home environments can be of great benefits to the working families and holiday makers and has a great commercial potential.

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Safety and Security of Remote Monitoring and Control of intelligent Home Environments

Survey/review study
A Survey on Evolved LoRa-Based Communication Technologies for Emerging Internet of Things Applications

Fang Yao 1,3, Yulong Ding 2,3,*, Shengguang Hong 2,4, and Shuang-Hua Yang 2,5,*


1 The Ta-tech company, Nanjing 210009, China
2 Shenzhen Key Laboratory of Safety and Security for Next Generation of Industrial Internet, Department of Electronics and Information Engineering, Shenzhen University, Shenzhen 518060, China
3 Department of Computer Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
4 The School of Computer Science and Technology, Harbin Institute of Technology, Harbin 150006, China
5 Department of Computer Science, University of Reading, West Berkshire RG6 6UR, United Kingdom
* Correspondence: dingyl@sustech.edu.cn; Shuang-hua.yang@reading.ac.uk 
 
 
Received: 17 September 2022
Accepted: 17 October 2022
Published: 22 December 2022
 

Abstract: The concept of Internet of Things (IoT) greatly extends the coverage area that human being is able to perceive, access, and even control. By connecting various “Things” to the Internet, the IoT makes it possible to measure and manage the physical world as needed. As one of the most widely adopted Low Power Wide Area network technologies, the Long-Range-Radio (LoRa) has the features of long range, low power, and robustness, and thus plays an important role in building IoT applications where IoT objects are connected to the internet at affordable costs. Since the development of LoRa, many IoT applications have adopted LoRa and achieved success in the market. Currently, IoT technologies keep evolving towards different fields, giving rise to multifarious IoT applications including industrial IoT, smart city IoT, healthcare IoT, and direct-to-satellite IoT. In the meantime, LoRa also keeps developing and finding its position in various IoT applications either as a main or complementary player. The objective of this survey is to (1) provide a fundamental understanding of the LoRa technology; (2) explore research activities studying LoRa based communication systems for new IoT applications; and (3) demonstrate how the LoRa technology works together with other technologies to deliver better IoT services to end users.

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A Survey on Evolved LoRa-Based Communication Technologies for Emerging Internet of Things Applications

The Radio Frequency Identification (RFID) system is a widely used Auto-ID technology today to identify and track objects and people in manufacturing, inventory management, retailing, and security applications. The Zigbee technology, which is a recently emerged network communication protocol based on the IEEE 802.15.4 standard, provides a self-organized mesh network topology with a power-effective, low data rate and multi-hop data transmission. The RFID system could profit some of its features by introducing the Zigbee technology into the existing RFID architectures, such as having extended effective range, improving network flexibility and having compatibility with other Zigbee enabled environment systems. In this paper we first discuss the possible benefits and applications while applying Zigbee to the different parts of the RFID system. Then an integrated Zigbee RFID system architecture is discussed and a demo system is described at the end of the paper.

Zigbee enabled radio frequency identification system

Using wireless sensor network (WSN) to provide environmental data is becoming an increasingly important topic in the research area of building a smart house. As the standard designed for low data rate and low cost wireless personal area network, the IEEE 802.15.4 standard is widely employed in the construction of home sensor networks to assist the smart house application with a real-time environment information infrastructure. However, its working frequency (2.4 GHz ISM band) and low transmission power (typically 1 mW) make the system easily open to interference caused by other powerful wireless systems or signals which also work on the same frequency band, especially by Wi-Fi (IEEE 802.11b) systems. In this paper, we analyze the factors, which cause interference of the IEEE 802.15.4 system by Wi-Fi, and propose an interference mitigation strategy which utilizing the interferer's transmission interval to enable the IEEE 802.15.4 network to maintain communications during times of interference.

Fang Yao

Papers

A zigbee-based home automation system

Safety and Security of Remote Monitoring and Control of intelligent Home Environments

A Survey on Evolved LoRa-Based Communication Technologies for Emerging Internet of Things Applications

Zigbee enabled radio frequency identification system

Mitigating interference caused by IEEE 802.11b in the IEEE 802.15.4 WSN within the environment of smart house