184 results found
Shi F, Qin Z, Wu D, et al., 2018, Effective truth discovery and fair reward distribution for mobile crowdsensing, Pervasive and Mobile Computing, Vol: 51, Pages: 88-103, ISSN: 1574-1192
© 2018 Elsevier B.V. By leveraging the sensing capabilities of consumer mobile devices, mobile crowdsensing (MCS) systems enable a number of new applications for Internet of Things (IoT), such as traffic management, environmental monitoring, and localisation. However, the sensing data collected from the crowd workers are of various qualities, making it difficult to discover the ground truth and maintain the fairness of incentivisation schemes. In this paper, we propose a truth discovery algorithm based on a two-stage Maximum Likelihood Estimator (MLE), which explicitly characterises the heterogeneous sensing capabilities of the crowd and is able to estimate ground truth accurately using only a small amount of data from IoT infrastructures. Moreover, based on the truth discovery algorithm, two reward distribution schemes, LRDS and MRDS, are proposed to ensure fairness of rewarding the crowd according to their effort levels. We evaluate the estimation accuracy of the truth discovery algorithm and the fairness of the reward distribution schemes using both simulations and real-world MCS campaigns. The evaluation results indicate that the proposed methods achieve superior performance compared with state-of-the-art methods in terms of estimation accuracy and fairness of reward distribution.
Bhatia L, Tomic I, McCann J, 2018, LPWA-MAC - a low power wide area network MAC protocol for cyber-physical system, The 16th ACM Conference on Embedded Networked Sensor Systems (SenSys 2018), Publisher: ACM, Pages: 361-362
Low-Power Wide-Area Networks (LPWANs) are being successfully used for the monitoring of large-scale systems that are delay-tolerant and which have low-bandwidth requirements. The next step would be instrumenting these for the control of Cyber-Physical Systems (CPSs) distributed over large areas which require more bandwidth, bounded delays and higher reliability or at least more rigorous guarantees therein. This paper presents LPWA-MAC, a novel Low Power Wide-Area network MAC protocol, that ensures bounded end-to-end delays, high channel utility and supports many of the different traffic patterns and data-rates typical of CPS.
Bhatia L, Boyle D, McCann J, 2018, Aerial interactions with wireless sensors, The 16th ACM Conference on Embedded Networked Sensor Systems (SenSys 2018), Pages: 373-374
Sensing systems incorporating unmanned aerial vehicles have the potential to enable a host of hitherto impractical monitoring applications using wireless sensors in remote and extreme environments. Their use as data collection and power delivery agents can overcome challenges such as poor communications reliability in difficult RF environments and maintenance in areas dangerous for human operatives. Aerial interaction with wireless sensors presents some interesting new challenges, including selecting or designing appropriate communications protocols that must account for unique practicalities like the effects of velocity and altitude. This poster presents a practical evaluation of the effects of altitude when collecting sensor data using an unmanned aerial vehicle. We show that for an otherwise disconnected link over a long distance (70m), by increasing altitude (5m) the link is created and its signal strength continues to improve over tens of metres. This has interesting implications for protocol design and optimal aerial route planning.
Kartakis S, Lu A, Mazo M, et al., 2018, Communication Schemes for Centralized and Decentralized Event-Triggered Control Systems, IEEE TRANSACTIONS ON CONTROL SYSTEMS TECHNOLOGY, Vol: 26, Pages: 2035-2048, ISSN: 1063-6536
Tomić I, Bhatia L, Breza MJ, et al., 2018, The Limits of LoRaWAN in Event-Triggered Wireless Networked Control Systems, Pages: 101-106
© 2018 IEEE. Wireless sensors and actuators offer benefits to large industrial control systems. The absence of wires for communication reduces the deployment cost, maintenance effort, and provides greater flexibility for sensor and actuator location and system architecture. These benefits come at a cost of a high probability of communication delay or message loss due to the unreliability of radio-based communication. This unreliability poses a challenge to contemporary control systems that are designed with the assumption of instantaneous and reliable communication. Wireless sensors and actuators create a paradigm shift in engineering energy-efficient control schemes coupled with robust communication schemes that can maintain system stability in the face of unreliable communication. This paper investigates the feasibility of using the low-power wide-area communication protocol LoRaWAN with an event-triggered control scheme through modelling in Matlab. We show that LoRaWAN is capable of meeting the maximum delay and message loss requirements of an event-triggered controller for certain classes of applications. We also expose the limitation in the use of LoRaWAN when message size or communication range requirements increase or the underlying physical system is exposed to significant external disturbances.
Ren X, Yu C-M, Yu W, et al., 2018, LoPub: high-dimensional crowdsourced data publication with local differential privacy, IEEE Transactions on Information Forensics and Security, Vol: 13, Pages: 2151-2166, ISSN: 1556-6013
High-dimensional crowdsourced data collected from numerous users produces rich knowledge about our society; however, it also brings unprecedented privacy threats to the participants. Local differential privacy (LDP), a variant of differential privacy, is recently proposed as a state-of-the-art privacy notion. Unfortunately, achieving LDP on high-dimensional crowdsourced data publication raises great challenges in terms of both computational efficiency and data utility. To this end, based on the expectation maximization (EM) algorithm and Lasso regression, we first propose efficient multi-dimensional joint distribution estimation algorithms with LDP. Then, we develop a local differentially private high-dimensional data publication algorithm (LoPub) by taking advantage of our distribution estimation techniques. In particular, correlations among multiple attributes are identified to reduce the dimensionality of crowdsourced data, thus speeding up the distribution learning process and achieving high data utility. Extensive experiments on real-world datasets demonstrate that our multivariate distribution estimation scheme significantly outperforms existing estimation schemes in terms of both communication overhead and estimation speed. Moreover, LoPub can keep, on average, 80% and 60% accuracy over the released datasets in terms of support vector machine and random forest classification, respectively.
Shi F, Qin Z, McCann JA, 2018, EventMe: Location-Based Event Content Distribution through Human Centric Device-to-Device Communications, IEEE International Conference on Communications (ICC), pp. 1-7. IEEE, 2018., Publisher: IEEE, ISSN: 1550-3607
Location-based information dissemination has become increasingly popular in the recent years. Extensive research work has been done on the matching of interested parties to event information via publish/subscribe systems. However, the rich content types of such location-specific data, especially when the data are presented in multimedia form, requires efficient methods with low cost to transfer the content to the subscribers. In this paper, the potential of utilising human centric device-to-device (D2D) communications to disseminate location-based event content is investigated. The human centric D2D data dissemination process is formulated as a task assignment problem, which can be modelled as a Integer Quadratically Constrained Quadratic Programming (IQCQP) problem. Since the IQCQP problem is in general NP-hard, a sub- optimal polynomial framework named EventMe is proposed, which is able to compute a solution with guaranteed lower bounds on data distribution capacity in terms of throughput. Through extensive evaluation using several real world datasets, it has shown that EventMe is able to improve the network throughput by 100%-500% compared to baseline methods. A prototype is developed and shows that it is practical to implement EventMe on mobile devices by generating minimal control data overhead.
Shi F, Qin Z, Wu D, et al., 2018, MPCSToken: Smart contract enabled fault-tolerant incentivisation for mobile P2P crowd services, Pages: 961-971
© 2018 IEEE. Mobile peer to peer (P2P) networks offer a huge potential for distributed mobile P2P crowd services (MPCS), which enable data and computational tasks to be offloaded and executed directly between mobile devices. Similar to centralised mobile crowd services, such as mobile crowdsensing, incentivisation mechanisms are core to encouraging mobile users to participate in MPCS systems. However, due to the impact of task execution failures and unreliable behaviours of mobile users (particularly task requesters), it is a daunting task to design and implement an incentivisation mechanism to cater for the needs of MPCS systems. In this paper, we propose a fault-tolerant incentivisation mechanism (FTIM) for MPCS systems. With conditional payment strategies, FTIM is proven to accommodate the requirements of two important application scenarios by achieving mechanism properties such as incentive compatibility, economic efficiency, individual rationality, and weak budget balance. Moreover, to tackle the practical challenges in implementing FTIM in the real world, we design a MPCSTo-ken smart contract to facilitate its service auction, task execution and payment settlement process. We implement the MPCSToken contract on Ethereum blockchain. Both real-world experiment and simulation results show that the system is cost effective for deployments and improves the overall mobile users' utility by exploring the opportunities offered by MPCS.
Zhao C, Yang S, Yan P, et al., 2018, DATA QUALITY GUARANTEE FOR CREDIBLE CACHING DEVICE SELECTION IN MOBILE CROWDSENSING SYSTEMS, IEEE WIRELESS COMMUNICATIONS, Vol: 25, Pages: 58-64, ISSN: 1536-1284
Mcgrane SJ, Acuto M, Artioli F, et al., 2018, Scaling the nexus: Towards integrated frameworks for analysing water, energy and food, Geographical Journal, ISSN: 0016-7398
The emergence of the water-energy-food (WEF) nexus has resulted in changes to the way we perceive our natural resources. Stressors such as climate change and population growth have highlighted the fragility of our WEF systems, necessitating integrated solutions across multiple scales. While a number of frameworks and analytical tools have been developed since 2011, a comprehensive WEF nexus tool remains elusive, hindered in part by our limited data and understanding of the interdependencies and connections across the WEF systems. To achieve this, the community of academics, practitioners and policy-makers invested in WEF nexus research are addressing several critical areas that currently remain as barriers. First, the plurality of scales (e.g., spatial, temporal, institutional, jurisdictional) necessitates a more comprehensive effort to assess interdependencies between water, energy and food, from household to institutional and national levels. Second, and closely related to scale, a lack of available data often hinders our ability to quantify physical stocks and flows of resources. Overcoming these barriers necessitates engaging multiple stakeholders, and using experiences and local insights to better understand nexus dynamics in particular locations or scenarios, and we exemplify this with the inclusion of a UK-based case study on exploring the nexus in a particular geographical area. We elucidate many challenges that have arisen across nexus research, including the impact of multiple scales in operation, and concomitantly, what impact these scales have on data accessibility. We assess some of the critical frameworks and tools that are applied by nexus researchers and articulate some of the steps required to develop from nexus thinking to an operationalisable concept, with a consistent focus on scale and data availability.
Breza M, Tomic I, McCann J, 2018, Failures from the environment, A report on the first FAILSAFE workshop, Pages: 40-45, ISSN: 0146-4833
© 2018 Association for Computing Machinery. All rights reserved. This document presents the views expressed in the submissions and discussions at the FAILSAFE workshop about the common problems that plague embedded sensor system deployments in the wild. We present analysis gathered from the submissions and the panel session of the FAILSAFE 2017 workshop held at the SenSys 2017 conference. The FAILSAFE call for papers specifically asked for descriptions of wireless sensor network (WSN) deployments and their problems and failures. The submissions, the questions raised at the presentations, and the panel discussion give us a sufficient body of work to review, and draw conclusions regarding the effect that the environment has as the most common cause of embedded sensor system failures.
Tahir Y, Yang S, McCann J, 2018, BRPL: Backpressure RPL for High-Throughput and Mobile IoTs, IEEE Transactions on Mobile Computing, Vol: 17, Pages: 29-43, ISSN: 1536-1233
Tomic I, McCann JA, 2017, A Survey of Potential Security Issues in Existing Wireless Sensor Network Protocols, IEEE INTERNET OF THINGS JOURNAL, Vol: 4, Pages: 1910-1923, ISSN: 2327-4662
Liu Y, Qin Z, Elkashlan M, et al., 2017, Non-Orthogonal Multiple Access in Large-Scale Heterogeneous Networks, IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS, Vol: 35, Pages: 2667-2680, ISSN: 0733-8716
Yadav P, McCann JA, Pereira T, 2017, Self-Synchronization in Duty-Cycled Internet of Things (IoT) Applications, IEEE INTERNET OF THINGS JOURNAL, Vol: 4, Pages: 2058-2069, ISSN: 2327-4662
Jackson G, Wilson D, Gallacher S, et al., 2017, Tales from the Wild: Lessons Learned from Creating a Living Lab
Wireless sensor networks in the past decade have become prevalent in areas such as environmental monitoring, hazard detection, and industrial IoT applications. Current research focuses on improving the energy efficiency, throughput, robustness, and resilience of such networks. Within this work, failures are rarely held up as something to be explored and discussed, as improvements and novelty are the traditionally highlighted outcomes. However, in order to undertake effective research, highlighting failures can help mitigate against them occurring in the future. In this paper, we wish to highlight failures in our work, times when engineering and social challenges were barriers to the completion of world class research. Three stakeholder driven case studies from the London Living Lab are chosen namely air quality, microclimate and urban bat monitoring. From these deployments, challenges are highlighted and the subsequent methods developed to overcome said challenges are explored with the view that future work may benefit from the outcomes of these experiences.
Kartakis S, Yang S, Mccann JA, 2017, Reliability or Sustainability: Optimal Data Stream Estimation and Scheduling in Smart Water Networks, ACM TRANSACTIONS ON SENSOR NETWORKS, Vol: 13, ISSN: 1550-4859
Zhao C, Yang S, Yang X, et al., 2017, Rapid, User-Transparent, and Trustworthy Device Pairing for D2D-Enabled Mobile Crowdsourcing, IEEE TRANSACTIONS ON MOBILE COMPUTING, Vol: 16, Pages: 2008-2022, ISSN: 1536-1233
Breza M, McCann J, 2017, Polite Broadcast Gossip for IOT Configuration Management
© 2017 IEEE. In this paper we present a protocol which can be used to form the basis of an Internet of Things (IOT) configuration management system. We motivate this discussion by focusing on a large and definitive class of IOT systems, Wireless Sensor Networks (WSN) and some important applications. We present a polite broadcast gossip dissemination algorithm which focuses on using a minimal amount of communication to update the configuration of a network of sensor nodes. We present analysis that the politeness of the algorithm does not inhibit its ability to function. The message savings of the algorithm is evaluated in simulation. We present test-bed results which show that our algorithm can disseminate metadata with roughly half of the communication overhead of a dissemination mechanism based on the one used by the IETF proposed standard Routing Protocol for Low Power and Lossy Networks (RPL).
Yang S, Adeel U, Tahir Y, et al., 2017, Practical Opportunistic Data Collection in Wireless Sensor Networks with Mobile Sinks, IEEE TRANSACTIONS ON MOBILE COMPUTING, Vol: 16, Pages: 1420-1433, ISSN: 1536-1233
Ren X, Yu CM, Yu W, et al., 2017, High-dimensional crowdsourced data distribution estimation with local privacy, Pages: 226-233
© 2016 IEEE. High-dimensional crowdsourced data collected from a large number of users may produc3 rich knowledge for our society but also bring unprecedented privacy threats to participants. Recently differential privacy has been proposed as an effective means to mitigate privacy concerns. However, existing work on differential privacy suffers from the 'curse of high-dimensionality' (data with multiple attributes) and high scalability (data with large scale records). Moreover, traditional methods of differential privacy were achieved via aggregation results, which cannot guarantee local privacy for distributed users in crowdsourced systems. To deal with these issues, in this paper we propose a novel scheme that can efficiently estimate multivariate joint distribution for high-dimensional data with local privacy. On the client side, we employ randomized response techniques to locally transform data from distributed users into privacy-preserving bit strings, which can prevent potential inside privacy attacks in crowdsourced systems. On the server side, the crowdsourced bit strings are aggregated for multivariate distribution estimation. Specifically, we first propose a multivariate version of the expectation maximization (EM) based algorithm to estimate the joint distribution of high dimensional data. To speed up the performance, unlike the EM-based method that needs to scan each user's bit string, we propose to use Lasso regression to obtain the distribution estimation from the aggregation information only once, which can significantly reduce the computation time for multivariate distribution estimation. Extensive experiments on real-world datasets demonstrate the efficiency of our multivariate distribution estimation scheme over existing estimation schemes.
Haghighi M, Qin Z, Carboni D, et al., 2017, Game theoretic and auction-based algorithms towards opportunistic communications in LPWA LoRa networks, Pages: 735-740
© 2016 IEEE. Low Power Wide Area (LPWA) networks have been the enabling technology for large-scale sensor and actuator networks. Low cost, energy-efficiency and longevity of such networks make them perfect candidates for smart city applications. LoRa is a new LPWA standard based on spread spectrum technology, which is suitable for sensor nodes enabling long battery life and bi-directional communication but with low data rates. In this paper, we will demonstrate a use-case inspired model in which, end-nodes with multiple radio transceivers (LoRa/WiFi/BLE) have the option to interconnect via multiple networks to improve communications resilience under the diverse conditions of a smart city of a billion devices. To facilitate this, each node has the ability to switch radio communications opportunistically and adaptively, and this is based on the application requirements and dynamic radio parameters.
Wu D, Arkhipov DI, Kim M, et al., 2017, ADDSEN: Adaptive Data Processing and Dissemination for Drone Swarms in Urban Sensing, IEEE TRANSACTIONS ON COMPUTERS, Vol: 66, Pages: 183-198, ISSN: 0018-9340
Johnson M, McCann J, Santer M, et al., 2017, On orbit validation of solar sailing control laws with thin-film spacecraft, The Fourth International Symposium on Solar Sailing, Publisher: Japan Space Forum
Many innovative approaches to solar sail mission and trajectory design have been proposed over the years, but very few ever have the opportunity to be validated on orbit with real spacecraft. Thin-Film Spacecraft/Lander/Rovers (TF-SLRs) are a new class of very low cost, low mass space vehicle which are ideal for inexpensively and quickly testing in flight new approaches to solar sailing. This paper describes using TF-SLR based micro solar sails to implement a generic solar sail test bed on orbit. TF-SLRs are high area-to-mass ratio (A/m) spacecraft developed for very low cost consumer and scientific deep space missions. Typically based on a 5 μm or thinner metalised substrate, they include an integrated avionics and payload system-on-chip (SoC) die bonded to the substrate with passive components and solar cells printed or deposited by Metal Organic Chemical Vapour Deposition (MOCVD). The avionics include UHF/S-band transceivers, processors, storage, sensors and attitude control provided by integrated magnetorquers and reflectivity control devices. Resulting spacecraft have a typical thickness of less than 50 μm, are 80 mm in diameter, and have a mass of less than 100 mg resulting in sail loads of less than 20 g/m2. TF-SLRs are currently designed for direct dispensing in swarms from free flying 0.5U Interplanetary CubeSats or dispensers attached to launch vehicles. Larger 160 mm, 320 mm and 640 mm diameter TF-SLRs utilizing a CubeSat compatible TWIST deployment mechanism that maintains the high A/m ratio are also under development. We are developing a mission to demonstrate the utility of these devices as a test bed for experimenting with a variety of mission designs and control laws. Batches of up to one hundred TF-SLRs will be released on earth escape trajectories, with each batch executing a heterogeneous or homogenous mixture of control laws and experiments. Up to four releases at different points in orbit are currently envisaged with experiments currently
Qin Z, McCann JA, 2017, Resource Efficiency in Low-Power Wide-Area Networks for IoT Applications, IEEE Global Communications Conference (GLOBECOM), Publisher: IEEE, ISSN: 2334-0983
Jackson G, Ciocoiu S, McCann JA, 2017, Solar Energy Harvesting Optimization for Wireless Sensor Networks, IEEE Global Communications Conference (GLOBECOM), Publisher: IEEE, ISSN: 2334-0983
Babazadeh M, Kartakis S, McCann JA, 2017, Highly-Distributed Sensor Processing using IoT for Critical Infrastructure Monitoring, 9th Annual Summit and Conference of the Asia-Pacific-Signal-and-Information-Processing-Association (APSIPA ASC), Publisher: IEEE, Pages: 1065-1074, ISSN: 2309-9402
Qin Z, Liu Y, Li GY, et al., 2017, Modelling and Analysis of Low-Power Wide-Area Networks, IEEE International Conference on Communications (ICC), Publisher: IEEE, ISSN: 1550-3607
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