- Email: [email protected]
Special issue: Wireless sensor and robot networks: Algorithms and experiments
Computer Communications 35 (2012) iii–iv
Contents lists available at SciVerse ScienceDirect
Computer Communications journal homepage: www.elsevier.com/locate/comcom
Editorial
Special issue: Wireless sensor and robot networks: Algorithms and experiments
The advent of nano-technology and advances in communications has made it technologically feasible and economically viable to develop low-power devices that integrate general-purpose computing with multi-purpose sensing and wireless communications capabilities. It is expected that wireless sensor networks (WSN) will have a significant impact on a wide array of applications, establishing a ubiquitous computing environment that will pervade society and redefining the way in which we live and work. Recently, in the attempt to integrate WSN in the fabric of human activities it has been recognized that it would be beneficial to augment sensor networks by robots. Robots are often sophisticated mobile entities (e.g., Unmanned Aerial Vehicles) that are able to make complex decisions and take appropriate actions on themselves, sensors and/or the environment. They sometimes may also be mobile entities (e.g., shuttle buses) that are already in the environment and provide simple value-added services. Robots interconnect either directly or via sensors. Wireless sensor and robot networks (WSRNs) are the confluence point where the two traditional fields WSN and robot networks meet, and nodes collaborate to accomplish distributed sensing and actuation tasks. Leveraged by the control and mobility of robots, the networking process and applications embrace a whole new set of possibilities. The objective of this special issue is to bring together state-of-the-art contributions on the design, specification, and implementation of architectures, algorithms and protocols for current and future applications of WSRN. Out of 41 submissions, we selected 15 contributions for publication after several rounds of review by invited experts and the guest editors. Mobility control methods are crucial for wireless sensor and robot network performance in many ways. In the paper ‘‘Team Formation and Steering Algorithms for Underwater Gliders using Acoustic Communications’’, in order to enable underwater gliders, which is a class of energy-efficient and propeller-less AUVs, the authors propose robust team formation and steering algorithms against ocean currents and acoustic channel impairments, relying on underwater acoustic communications. In the paper ‘‘ORACLE: Mobility Control in Wireless Sensor and Actor Networks’’, Ota et al. study actors’ mobility control in wireless sensor and actor networks for efficient events detecting in terms of time and energy consumption. They present an innovative approach ORACLE to tackle the challenging scenario that actors can predict events before sensors detection and migrate to the areas where the event might occur. The paper ‘‘Biconnecting a Network of Mobile Robots using Virtual Angular Forces’’ by Casteigts et al. proposes a new solution to the problem of self-deploying a network of wireless mobile robots with simultaneous consideration to several criteria including fault-tolerance (biconnectivity) of the resulting network,
http://dx.doi.org/10.1016/S0140-3664(12)00138-7
coverage, diameter, and quantity of movement required to complete the deployment. The paper ‘‘Maximization in Mobile Robot Networks Using an Evolving Neural Network’’ by Natalizio et al. describes a dynamic coverage approach that integrates both neural network and genetic algorithm in determining the sensors’ movements for WSRNs. How to design energy efficient algorithms to prolong the lifetime of WSRNs also is a challenging problem. Abdulla et al. in ‘‘Extending the Lifetime of Wireless Sensor Networks: A Hybrid Routing Algorithm’’ classify the existing routing algorithms developed for wireless sensor networks into two classes, i.e., flat multihop routing algorithms and hierarchical multi-hop routing algorithms. A hybrid multi-hop routing algorithm is further proposed, which prolongs the network lifetime of wireless sensor networks by dealing with the hotspot problem. Chen et al. propose a novel cooperative automatic retransmission request (CARQ) protocol for wireless sensor networks to minimize the energy consumption as well as prolongs the network life in ‘‘Throughput and Energy Efficiency of a Novel Cooperative ARQ Strategy for Wireless Sensor Networks’’. They also propose a general discrete time Markov chain model to analyze the throughput and energy efficiency. The paper entitled ‘‘Centrality-based Power Control for Hot-spot Mitigation in Multi-hop Wireless Networks’’ by Pathak et al. proposes the centrality-based power control for sensor networks to balance the relay load among nodes and improve nodes’ energy efficiency eventually. The paper entitled ‘‘Constructing Efficient Rotating Backbones in Wireless Sensor Networks using Graph Coloring’’ by Mahjoub et al. presents both centralized and distributed algorithms for selecting backbones with disjoint node sets, which can rotate their activity for coverage and routing, and thus extend network lifetime. Chao et al. propose a systematic method to assist the designer to decide the queue size of sensor node to ensure that the optimal queue size can be found to obtain minimum energy consumption in ‘‘A Queue-Based Prolong Lifetime Methods for Wireless Sensor Node’’. Introducing mobile robots into sensor networks is expected to improve target localization and tracking. Cheng et al. in ‘‘On Optimizing Sensing Quality with Guaranteed Coverage in Autonomous Mobile Sensor Networks’’ consider target tracking based on mobile wireless sensor networks while guaranteeing area coverage. They show that, in order to improve the target sensing quality, the mobile sensors should move toward the target, while their movements are rather constrained by a given coverage threshold in consideration of guaranteeing the coverage. Zhao et al. introduces a novel approach to localize random targets in sensor networks using mobile robot, without any GPS devices or preloaded global information in ‘‘Local Information Guided Autonomous Exploration in Sensor Networks: Algorithms and Experiments’’.
iv
Editorial / Computer Communications 35 (2012) iii–iv
The last four papers concern protocol and systems design issues in WSRNs. The paper ‘‘Novel 2-hop Coloring Algorithm for Timeslot Assignment of Newly Deployed Sensor Nodes without ID in Wireless Sensor and Robot Networks’’ focuses on channel assignment in the initialization of newly deployed sensor networks and proposes a distributed time-slot assignment algorithm without the requirement of node ID information. The paper ‘‘Structure-free Real-time Data Aggregation in Wireless Sensor Networks’’ designs a structure-free real-time data aggregation protocol using two mechanisms for temporal and spatial convergence of packets- judiciously waiting policy and real-time data-aware anycasting policy. Lin et al. highlight three important issues to be addressed for the environmental monitoring system supported by WSRN in ‘‘APS: Distributed Air Pollution Sensing System on Wireless Sensor and Robot’’. They design and implement a distributed Air Pollution Sensing (APS) system on the WSRNs to monitor the air quality in the urban environment. The paper ‘‘GPS-Free Directional Localization via Dual Wireless Radios’’ by Akcan et al. proposes a novel directional localization algorithm, DWRL, which performs accurate node localizations in the plane using only distances between nodes, without the use of a GPS or nodes with known positions. We hope that this special issue will provide readers with insights and valuable information on the design, specification, and
implementation of wireless sensor and robot networks. We are also grateful to all the authors who submitted papers, the reviewers who provided timely and informative reviews on the submissions, and Professor Marco Conti, Editor-in-Chief of Computer Communications, for his support throughout the process of producing this special issue.
Guest Editors Jiming Chen Department of Control Science and Engineering, Zhejiang University, China E-mail address: [email protected] Hannes Frey Department of Computer Science, University of Paderborn, Germany E-mail address: [email protected] Xu Li Department of Electrical and Computer Engineering, University of Waterloo, Canada E-mail address: [email protected]
Contents lists available at SciVerse ScienceDirect
Computer Communications journal homepage: www.elsevier.com/locate/comcom
Editorial
Special issue: Wireless sensor and robot networks: Algorithms and experiments
The advent of nano-technology and advances in communications has made it technologically feasible and economically viable to develop low-power devices that integrate general-purpose computing with multi-purpose sensing and wireless communications capabilities. It is expected that wireless sensor networks (WSN) will have a significant impact on a wide array of applications, establishing a ubiquitous computing environment that will pervade society and redefining the way in which we live and work. Recently, in the attempt to integrate WSN in the fabric of human activities it has been recognized that it would be beneficial to augment sensor networks by robots. Robots are often sophisticated mobile entities (e.g., Unmanned Aerial Vehicles) that are able to make complex decisions and take appropriate actions on themselves, sensors and/or the environment. They sometimes may also be mobile entities (e.g., shuttle buses) that are already in the environment and provide simple value-added services. Robots interconnect either directly or via sensors. Wireless sensor and robot networks (WSRNs) are the confluence point where the two traditional fields WSN and robot networks meet, and nodes collaborate to accomplish distributed sensing and actuation tasks. Leveraged by the control and mobility of robots, the networking process and applications embrace a whole new set of possibilities. The objective of this special issue is to bring together state-of-the-art contributions on the design, specification, and implementation of architectures, algorithms and protocols for current and future applications of WSRN. Out of 41 submissions, we selected 15 contributions for publication after several rounds of review by invited experts and the guest editors. Mobility control methods are crucial for wireless sensor and robot network performance in many ways. In the paper ‘‘Team Formation and Steering Algorithms for Underwater Gliders using Acoustic Communications’’, in order to enable underwater gliders, which is a class of energy-efficient and propeller-less AUVs, the authors propose robust team formation and steering algorithms against ocean currents and acoustic channel impairments, relying on underwater acoustic communications. In the paper ‘‘ORACLE: Mobility Control in Wireless Sensor and Actor Networks’’, Ota et al. study actors’ mobility control in wireless sensor and actor networks for efficient events detecting in terms of time and energy consumption. They present an innovative approach ORACLE to tackle the challenging scenario that actors can predict events before sensors detection and migrate to the areas where the event might occur. The paper ‘‘Biconnecting a Network of Mobile Robots using Virtual Angular Forces’’ by Casteigts et al. proposes a new solution to the problem of self-deploying a network of wireless mobile robots with simultaneous consideration to several criteria including fault-tolerance (biconnectivity) of the resulting network,
http://dx.doi.org/10.1016/S0140-3664(12)00138-7
coverage, diameter, and quantity of movement required to complete the deployment. The paper ‘‘Maximization in Mobile Robot Networks Using an Evolving Neural Network’’ by Natalizio et al. describes a dynamic coverage approach that integrates both neural network and genetic algorithm in determining the sensors’ movements for WSRNs. How to design energy efficient algorithms to prolong the lifetime of WSRNs also is a challenging problem. Abdulla et al. in ‘‘Extending the Lifetime of Wireless Sensor Networks: A Hybrid Routing Algorithm’’ classify the existing routing algorithms developed for wireless sensor networks into two classes, i.e., flat multihop routing algorithms and hierarchical multi-hop routing algorithms. A hybrid multi-hop routing algorithm is further proposed, which prolongs the network lifetime of wireless sensor networks by dealing with the hotspot problem. Chen et al. propose a novel cooperative automatic retransmission request (CARQ) protocol for wireless sensor networks to minimize the energy consumption as well as prolongs the network life in ‘‘Throughput and Energy Efficiency of a Novel Cooperative ARQ Strategy for Wireless Sensor Networks’’. They also propose a general discrete time Markov chain model to analyze the throughput and energy efficiency. The paper entitled ‘‘Centrality-based Power Control for Hot-spot Mitigation in Multi-hop Wireless Networks’’ by Pathak et al. proposes the centrality-based power control for sensor networks to balance the relay load among nodes and improve nodes’ energy efficiency eventually. The paper entitled ‘‘Constructing Efficient Rotating Backbones in Wireless Sensor Networks using Graph Coloring’’ by Mahjoub et al. presents both centralized and distributed algorithms for selecting backbones with disjoint node sets, which can rotate their activity for coverage and routing, and thus extend network lifetime. Chao et al. propose a systematic method to assist the designer to decide the queue size of sensor node to ensure that the optimal queue size can be found to obtain minimum energy consumption in ‘‘A Queue-Based Prolong Lifetime Methods for Wireless Sensor Node’’. Introducing mobile robots into sensor networks is expected to improve target localization and tracking. Cheng et al. in ‘‘On Optimizing Sensing Quality with Guaranteed Coverage in Autonomous Mobile Sensor Networks’’ consider target tracking based on mobile wireless sensor networks while guaranteeing area coverage. They show that, in order to improve the target sensing quality, the mobile sensors should move toward the target, while their movements are rather constrained by a given coverage threshold in consideration of guaranteeing the coverage. Zhao et al. introduces a novel approach to localize random targets in sensor networks using mobile robot, without any GPS devices or preloaded global information in ‘‘Local Information Guided Autonomous Exploration in Sensor Networks: Algorithms and Experiments’’.
iv
Editorial / Computer Communications 35 (2012) iii–iv
The last four papers concern protocol and systems design issues in WSRNs. The paper ‘‘Novel 2-hop Coloring Algorithm for Timeslot Assignment of Newly Deployed Sensor Nodes without ID in Wireless Sensor and Robot Networks’’ focuses on channel assignment in the initialization of newly deployed sensor networks and proposes a distributed time-slot assignment algorithm without the requirement of node ID information. The paper ‘‘Structure-free Real-time Data Aggregation in Wireless Sensor Networks’’ designs a structure-free real-time data aggregation protocol using two mechanisms for temporal and spatial convergence of packets- judiciously waiting policy and real-time data-aware anycasting policy. Lin et al. highlight three important issues to be addressed for the environmental monitoring system supported by WSRN in ‘‘APS: Distributed Air Pollution Sensing System on Wireless Sensor and Robot’’. They design and implement a distributed Air Pollution Sensing (APS) system on the WSRNs to monitor the air quality in the urban environment. The paper ‘‘GPS-Free Directional Localization via Dual Wireless Radios’’ by Akcan et al. proposes a novel directional localization algorithm, DWRL, which performs accurate node localizations in the plane using only distances between nodes, without the use of a GPS or nodes with known positions. We hope that this special issue will provide readers with insights and valuable information on the design, specification, and
implementation of wireless sensor and robot networks. We are also grateful to all the authors who submitted papers, the reviewers who provided timely and informative reviews on the submissions, and Professor Marco Conti, Editor-in-Chief of Computer Communications, for his support throughout the process of producing this special issue.
Guest Editors Jiming Chen Department of Control Science and Engineering, Zhejiang University, China E-mail address: [email protected] Hannes Frey Department of Computer Science, University of Paderborn, Germany E-mail address: [email protected] Xu Li Department of Electrical and Computer Engineering, University of Waterloo, Canada E-mail address: [email protected]