http://www.eecs.ucf.edu/~dcm/Teaching/COT4810-Spring2011/Literature/SensorNetworksSurvey.pdf

Wireless sensor networks: a survey

http://www.csun.edu/~andrzej/COMP529-S05/papers/Mesh%20Networks%20Survey.pdf

Wireless mesh networks: a survey

In the last years, wireless sensor networks (WSNs) have gained increasing attention from both the research community and actual users. As sensor nodes are generally battery-powered devices, the critical aspects to face concern how to reduce the energy consumption of nodes, so that the network lifetime can be extended to reasonable times. In this paper we first break down the energy consumption for the components of a typical sensor node, and discuss the main directions to energy conservation in WSNs. Then, we present a systematic and comprehensive taxonomy of the energy conservation schemes, which are subsequently discussed in depth. Special attention has been devoted to promising solutions which have not yet obtained a wide attention in the literature, such as techniques for energy efficient data acquisition. Finally we conclude the paper with insights for research directions about energy conservation in WSNs.

/pdf/energy-conservation-in-wireless-sensor-networks-a-survey-1bl7d2obnm.pdf

Energy conservation in wireless sensor networks: A survey

The objective of this paper is to give a comprehensive introduction to applied cryptography with an engineer or computer scientist in mind. The emphasis is on the knowledge needed to create practical systems which supports integrity, confidentiality, or authenticity. Topics covered includes an introduction to the concepts in cryptography, attacks against cryptographic systems, key use and handling, random bit generation, encryption modes, and message authentication codes. Recommendations on algorithms and further reading is given in the end of the paper. This paper should make the reader able to build, understand and evaluate system descriptions and designs based on the cryptographic components described in the paper.

[서평]「Applied Cryptography」

Energy harvesting generators are attractive as inexhaustible replacements for batteries in low-power wireless electronic devices and have received increasing research interest in recent years. Ambient motion is one of the main sources of energy for harvesting, and a wide range of motion-powered energy harvesters have been proposed or demonstrated, particularly at the microscale. This paper reviews the principles and state-of-art in motion-driven miniature energy harvesters and discusses trends, suitable applications, and possible future developments.

/pdf/energy-harvesting-from-human-and-machine-motion-for-wireless-3lsf4oudvo.pdf

Energy Harvesting From Human and Machine Motion for Wireless Electronic Devices

A cyberphysical network of insect biobots or biological robots could aid first-responders for search-and-rescue applications in uncertain disaster environments. In such networks, the nodes are insect biobots equipped with miniature backpacks utilizing a system-on-chip. These applications demand fine-grained, real-time localization of the sensor nodes. In this paper, we use a combination of radio-frequency and acoustic signal transmission to estimate the distance between two nodes with an aim of localizing the biobotic sensor nodes. We describe how digital processing, peak detection, and noise mitigation can be applied to meet the severe resource constraints of the specific application, yet yielding average localization errors of 12 cm within the effective range.

Towards acoustic localization for biobotic sensor networks

Time synchronization is a fundamental problem in any distributed system. In particular, wireless sensor networks require scalable time synchronization for implementing distributed tasks on multiple sensor nodes. This paper proposes an energy efficient Coefficient Exchange Synchronization Protocol (CESP) based on a receiver-receiver synchronization scheme that minimizes the impact of access-time delays. Most of the existing synchronization protocols focus on improving the synchronization accuracy while neglecting energy consumption. The proposed time synchronization protocol achieves a synchronization accuracy as good as the classic Reference Broadcast Synchronization (RBS) protocol but resulting in a dramatic reduction on communication overhead to achieve a low energy consumption. CESP works in a fundamentally different way from RBS: in order to synchronize two receivers, RBS exchanges all beacon packets between the two receivers, while CESP receivers first process a large number of received beacon packets and only exchange the minimum amount of information between the two receivers, i.e., synchronization coefficients. The synchronization performance is evaluated and compared with that of other well-known synchronization protocols.

CESP: A power efficient, accurate coefficient exchange synchronization protocol

Reliable and long-range wireless communications carry critical importance for remote identification (ID) of unmanned aerial systems (UAS). Federal Aviation Authority (FAA) in the United States has recently released rules that describe how drones can broadcast their ID and location information, without mandating a specific radio access technology. In this paper, we study LoRa as a candidate technology for drone remote ID. We first provide a brief overview of the recent FAA rules on drone remote ID released in December 2020. Subsequently, we provide preliminary results based on ray tracing and MATLAB simulations that evaluate the reliability and range of LoRa for UAS remote ID scenarios. Two different LoRa multi-user interference scenarios are considered: in one scenario, the interferer uses the same spreading factor (SF) as the desired user, while in another scenario, desired and interfering user SFs are different. Our results quantify the performance gains that may be obtained under different interference conditions, using various coding rates and SFs.

Use of LoRa for UAV Remote ID with Multi-User Interference and Different Spreading Factors

Motivated by the applications of parallel and distributed computing in m-D systems, this paper analyzes the effect of time-variant communication delays on the stability of 2-D systems. The time-variant communication delays are at first modeled and then used in the formulation of the 2-D Roesser local state space model. The arising overall dynamic system model is of uncertain, shift-variant form and it is described by finite uncertainty sets. The result is a sufficient condition for stability of the described process.

Stability of 2-D distributed processes with time-variant communication delays

The fifth generation (5G) mobile technology is being developed to meet the ever-increasing demands for cellular capacity. 5G is poised to be a critical enabler in various verticals. Millimeter waves (mmWaves), massive multi input multi output (MIMO) antenna arrays, and unmanned aerial vehicles (UAVs) are three key components that are being investigated in the context of 5G, which can jointly be used to support applications such as cellular-connected drones. To support such use cases, it is essential to study the propagation characteristics of ground to air (GA) mmWave links, for which there are very limited studies in the existing literature. In this work, we perform ray tracing simulations using Remcomm Wireless Insite software to compare ground and aerial coverage using mmWave communication links. Two sets of sectored antennas were used at the base station (BS), both of which use the same frequency spectrum. One antenna set was tilted up to serve aerial users while the other was tilted down to serve ground users. Our findings indicate that coverage is determined by shadowing due to buildings, path loss, and the angular interference between the beams of the two antenna sets. It was also observed that the coverage for aerial users is approximately twice that for ground users. Further, using sharper beams, of width 10 or less, is desirable as it makes spectrum reuse between aerial and ground users more feasible, enables users to be placed closely to each other and also increases the range, particularly for ground users. Along with narrower beams, MIMO beamforming techniques may be used to increase network capacity in dense urban areas.

Mihail L. Sichitiu

Papers

Towards acoustic localization for biobotic sensor networks

CESP: A power efficient, accurate coefficient exchange synchronization protocol

Use of LoRa for UAV Remote ID with Multi-User Interference and Different Spreading Factors

Stability of 2-D distributed processes with time-variant communication delays

Coverage Analysis for Ground and Aerial Users in mmWave Cellular Networks in Urban Settings