Swedish Institute of Computer Science

Displaying 1-40 of 52 results

  • White Papers // May 2012

    Efficient Mobile Data Collection With Mobile Collect

    The main task of most deployed wireless sensor networks is data collection. While a number of solutions have been designed for static networks, there are currently no widely used data collection algorithms for mobile sensor networks. In this paper, the authors concentrate on scenarios where many nodes, both data sources...

    Provided By Swedish Institute of Computer Science

  • White Papers // Apr 2012

    Do Sensor Networks Need Mobile MAC Protocols?

    There exists a number of MAC protocols targeted for mobile scenarios. These include MMAC, MS-MAC and AM-MAC. These MAC protocols have in common that they seem to be evaluated only in simulation. This might indicate that these MAC are either too complex to use or they are not needed, at...

    Provided By Swedish Institute of Computer Science

  • White Papers // Mar 2012

    Zooming Into Radio Events by Bus Snooping

    In this paper, the authors advocate the use of bus snooping to trace radio events. Highly precise and un-intrusive, the technique leads to potentially more efficient code and enables more insightful protocol analysis than conventional code instrumentation techniques. Communication between Cooperating Objects is typically carried out over a multiple-layer protocol...

    Provided By Swedish Institute of Computer Science

  • White Papers // Feb 2012

    Scalable Mining of Common Routes in Mobile Communication Network Traffic Data

    A probabilistic method for inferring common routes from mobile communication network traffic data is presented. Besides providing mobility information, valuable in a multitude of application areas, the method has the dual purpose of enabling efficient coarse-graining as well as anonymisation by mapping individual sequences onto common routes. The approach is...

    Provided By Swedish Institute of Computer Science

  • White Papers // Feb 2012

    The Bus Goes Wireless: Routing-Free Data Collection With QoS Guarantees in Sensor Networks

    The authors present the Low-power Wireless Bus (LWB), a new communication paradigm for QoS-aware data collection in low-power sensor networks. The LWB maps all communication onto network floods by using Glossy, an efficient flooding architecture for wireless sensor networks. Therefore, unlike current solutions, the LWB requires no information of the...

    Provided By Swedish Institute of Computer Science

  • White Papers // Jan 2012

    The ContikiMAC Radio Duty Cycling Protocol

    Low-power wireless devices must keep their radio transceivers off as much as possible to reach a low power consumption, but must wake up often enough to be able to receive communication from their neighbors. This paper describes the ContikiMAC radio duty cycling mechanism, the default radio duty cycling mechanism in...

    Provided By Swedish Institute of Computer Science

  • White Papers // Dec 2011

    Multi-Channel Two-Way Time of Flight Sensor Network Ranging

    Two-way time of Flight (ToF) ranging is one of the most interesting approaches for localization in wireless sensor networking since previous ToF ranging approaches using Commercial Off-The-Shelf (COTS) devices have achieved good accuracy. The COTS-based approaches were, however, evaluated only in line-of-sight conditions. In this paper, the authors extend ToF...

    Provided By Swedish Institute of Computer Science

  • White Papers // Nov 2011

    Middleware For Wireless Sensor Networks: An Outlook

    In modern distributed computing, applications are rarely built directly atop operating system facilities, e.g., sockets. Higher-level middleware abstractions and systems are often employed to simplify the programmer's chore or to achieve interoperability. In contrast, real-world Wireless Sensor Network (WSN) applications are almost always developed by relying directly on the operating...

    Provided By Swedish Institute of Computer Science

  • White Papers // Nov 2011

    Precise Packet Loss Pattern Generation by Intentional Interference

    Intermediate-quality links often cause vulnerable connectivity in wireless sensor networks, but packet losses caused by such volatile links are not easy to trace. In order to equip link layer protocol designers with a reliable test and debugging tool, the authors develop a reactive interferer to generate packet loss patterns precisely....

    Provided By Swedish Institute of Computer Science

  • White Papers // Sep 2011

    Hidden Terminal-Aware Contention Resolution With an Optimal Distribution

    Achieving low-power operation in wireless sensor networks with high data load or bursty traffic is challenging. The hidden terminal problem is aggravated with increased amounts of data in which traditional backoff-based contention resolution mechanisms fail or induce high latency and energy costs. The authors analyze and optimize Strawman, a receiver-initiated...

    Provided By Swedish Institute of Computer Science

  • White Papers // May 2011

    Low-Power Interoperability for the IPv6-Based Internet of Things

    The Internet of Things requires interoperability and low power consumption, but interoperability and low power consumption have thus far been mutually exclusive. This talk outlines the challenges in attaining low power operation for the IPv6-based Internet of Things, how this affects interoperability, and what must be done to combine the...

    Provided By Swedish Institute of Computer Science

  • White Papers // Apr 2011

    Leveraging IP for Sensor Network Deployment

    Ease of deployment has always been seen as a major selling point of wireless sensor networks, yet experience has shown deployment to be difficult. The authors argue that parts of these difficulties have come from the lack of a generic networking layer and of well-tested, generic transport protocols in traditional...

    Provided By Swedish Institute of Computer Science

  • White Papers // Apr 2011

    The Politecast Communication Primitive for Low-Power Wireless

    In low-power wireless networks, nodes need to duty cycle their radio transceivers to achieve a long system lifetime. Counter-intuitively, in such networks broadcast becomes expensive in terms of energy and bandwidth since all neighbors must be woken up to receive broadcast messages. The authors argue that there is a class...

    Provided By Swedish Institute of Computer Science

  • White Papers // Mar 2011

    Powertrace: Network-Level Power Profiling for Low-Power Wireless Networks

    Low-power wireless networks are quickly becoming a critical part of peoples' everyday infrastructure. Power consumption is a critical concern, but power measurement and estimation is a challenge. The authors present Powertrace, which to the best of their knowledge is the first system for network-level power profiling of low-power wireless systems....

    Provided By Swedish Institute of Computer Science

  • White Papers // Mar 2011

    Link Quality Estimation for Future Cooperating Objects

    In order to cooperate, smart objects need to communicate using wireless communication. Wireless communication, however, is inherently unreliable. Towards this end, the sensor networking community has developed a number of metrics for link quality estimation. Most of these metrics, however, are designed for static sensor networks whereas cooperating objects in...

    Provided By Swedish Institute of Computer Science

  • White Papers // Feb 2011

    Long-Term Adaptation and Distributed Detection of Local Network Changes

    The authors present a statistical approach to distributed detection of local latency shifts in networked systems. For this purpose, response delay measurements are performed between neighbouring nodes via probing. The expected probe response delay on each connection is statistically modelled via parameter estimation. Adaptation to drifting delays is accounted for...

    Provided By Swedish Institute of Computer Science

  • White Papers // Feb 2011

    Towards Distributed and Adaptive Detection and Localisation of Network Faults

    The authors present a statistical probing-approach to distributed fault-detection in networked systems, based on autonomous configuration of algorithm parameters. Statistical modelling is used for detection and localisation of network faults. A detected fault is isolated to a node or link by collaborative fault-localisation. From local measurements obtained through probing between...

    Provided By Swedish Institute of Computer Science

  • White Papers // Jan 2011

    Cautious Weight Tuning for Link State Routing Protocols

    Link state routing protocols are widely used for intradomain routing in the Internet. These protocols are simple to administer and automatically update paths between sources and destinations when the topology changes. However, finding link weights that optimize network performance for a given traffic scenario is computationally hard. The situation is...

    Provided By Swedish Institute of Computer Science

  • White Papers // Jan 2011

    Poster Abstract: Network Coding With Limited Overhearing

    The two key benefits of network coding are increased reliability and throughput. Most network coding approaches for wireless networks rely on overhearing neighboring transmissions. Overhearing in sensor networks, however, is not energy-efficient. In this paper, the authors extend GinMAC, a state-of-the-art MAC protocol, applying network coding with limited overhearing. The...

    Provided By Swedish Institute of Computer Science

  • White Papers // Jan 2011

    Demo Abstract: Realistic Simulation of Radio Interference in COOJA

    Radio interference drastically affects the reliability and robustness of wireless communications. As wireless sensor network protocols are frequently designed and tested in simulation environments first, it is important to have simulation tools that provide means to study the impact of radio interference. Radio propagation models available in simulation environments are...

    Provided By Swedish Institute of Computer Science

  • White Papers // Jan 2011

    Cross-Level Sensor Network Simulation With COOJA

    Simulators for wireless sensor networks are a valuable tool for system development. However, current simulators can only simulate a single level of a system at once. This makes system development and evolution difficult since developers cannot use the same simulator for both high-level algorithm development and low-level development such as...

    Provided By Swedish Institute of Computer Science

  • White Papers // Jan 2011

    Using Protothreads for Sensor Node Programming

    Wireless sensor networks consist of tiny devices that usually have severe resource constraints in terms of energy, processing power and memory. In order to work efficiently within the constrained memory, many operating systems for such devices are based on an event-driven model rather than on multi-threading. While event-driven systems allow...

    Provided By Swedish Institute of Computer Science

  • White Papers // Jan 2011

    Experimental Evaluation of Lifetime Bounds for Wireless Sensor Networks

    In this paper the authors present a method for experimental lifetime measurements of sensor networks. Despite the importance of experimental validation, none of the lifetime models proposed so far has been validated experimentally. One of the reasons for the absence of practical validations might be the long lifetime of batteries...

    Provided By Swedish Institute of Computer Science

  • White Papers // Jan 2011

    Contiki - A Lightweight and Flexible Operating System for Tiny Networked Sensors

    Wireless sensor networks are composed of large numbers of tiny networked devices that communicate untethered. For large scale networks it is important to be able to dynamically download code into the network. In this paper the authors present Contiki, a lightweight operating system with support for dynamic loading and replacement...

    Provided By Swedish Institute of Computer Science

  • White Papers // Dec 2010

    The Announcement Layer: Beacon Coordination for the Sensornet Stack

    Sensornet protocols periodically broadcast beacons for neighborhood information advertisement, but beacon transmissions are costly when power-saving radio duty cycling mechanisms are used. The authors show that piggybacking multiple beacons in a single transmission significantly reduces transmission costs and argue that this shows the need for a new layer in the...

    Provided By Swedish Institute of Computer Science

  • White Papers // Oct 2010

    Efficient Content Distribution in an Information-Centric Hybrid Mobile Network

    Information or content centric networking is believed by many to have great potential to be the appropriate networking paradigm for the future Internet. In information centric networking, focus is shifted from the end-points in the network to the information objects themselves, with less care being placed on from where the...

    Provided By Swedish Institute of Computer Science

  • White Papers // Sep 2010

    Evaluation of an Electronically Switched Directional Antenna for Real-World Low-PowerWireless Networks

    The authors present the real-world evaluation of SPIDA, an electronically switched directional antenna. Compared to most existing work in the field, SPIDA is practical as well as inexpensive. They interface SPIDA with an off-the-shelf sensor node which provides one with a fully working real-world prototype. The authors assess the performance...

    Provided By Swedish Institute of Computer Science

  • White Papers // Sep 2010

    The Look, the Feel and the Action: Making Sets of ActDresses for Robotic Movement

    The authors present a series of design explorations for controlling autonomous robotic movement based on a metaphor of clothing and accessorising. From working with various sketches, scenarios and prototypes they identify a number of particular features of this form of interaction, as well potential challenges for designers of other systems...

    Provided By Swedish Institute of Computer Science

  • White Papers // Sep 2010

    Sepidar: Incentivized Market-Based P2P Live-Streaming on the Gradient Overlay Network

    Live streaming of video content using overlay networks has gained widespread adoption on the Internet. This paper presents Sepidar, a distributed market-based model, which builds and maintains overlay network trees, which are approximately minimal height, for delivering live media as a number of substreams. A streaming tree is constructed for...

    Provided By Swedish Institute of Computer Science

  • White Papers // Jun 2010

    A Framework for WirelessHART Simulations

    Due to stringent timing requirements of the WirelessHART protocol, the authors need to extend previously known hybrid simulation approaches with WirelessHART specific functionality. Because of intermediary devices that connect simulation and real environments a communication delay significantly exceeds time boundaries of a WirelessHART slot. The authors' solution is to add...

    Provided By Swedish Institute of Computer Science

  • White Papers // May 2010

    StrawMAN: Making Sudden Traffic Surges Graceful in Low-Power Wireless Networks

    To ensure a long lifetime, sensor networks must operate with a low duty cycle, but the duty cycle must be high enough for the network to handle expected peak traffic loads. Being dimensioned for peak traffic rather than regular traffic leads to shorter lifetimes than necessary. The authors present StrawMAN,...

    Provided By Swedish Institute of Computer Science

  • White Papers // Mar 2010

    Energy Framework: An Extensible Framework for Simulating Battery Consumption in Wireless Networks

    This paper presents the Energy Framework, an extensible OMNeT++ framework for modeling battery consumption in wireless networks, particularly sensor networks. The Energy Framework is highly modular, separating modeling of the internal state of the battery from the modeling of operations that consume energy. This structure enables functionality that is not...

    Provided By Swedish Institute of Computer Science

  • White Papers // Feb 2010

    Demo Abstract: Smart Antennas Made Practical: The SPIDA Way

    Smart antennas are a specific type of directional antenna able to dynamically control the gain as a function of direction. This contrasts with more traditional directional antennas, where the dynamic ability is missing, and with omni-directional antennas, which are designed to have equal gain in all directions. Because of these...

    Provided By Swedish Institute of Computer Science

  • White Papers // Jan 2010

    Poster Abstract: Storage-Centric Debugging of Performance Problems in Sensor Networks

    After almost ten years of research into sensor networks, deployments continue to fail. Such failures are due to the distributed nature of sensor networks and the complex interactions of protocols. A variety of debugging tools have been developed to determine the exact causes of failures, and to mitigate the poor...

    Provided By Swedish Institute of Computer Science

  • White Papers // Jan 2010

    Secure Communication in WirelessHART and Its Integration With Legacy HART

    The WirelessHART is a new standard for Industrial Process Automation and Control, formally released in September 2007. WirelessHART specifications are very well organized in all aspects except security as there are no separate specifications that document security requirements, the security is limited and spread throughout the WirelessHART specifications, and it...

    Provided By Swedish Institute of Computer Science

  • White Papers // Jan 2010

    Assessing Security Risk to a Network Using a Statistical Model of Attacker Community Competence

    The authors propose a novel approach for statistical risk modeling of network attacks that lets an operator perform risk analysis using a data model and an impact model on top of an attack graph in combination with a statistical model of the attacker community exploitation skill. The data model describes...

    Provided By Swedish Institute of Computer Science

  • White Papers // Dec 2009

    Distributed Detection of Latency Shifts in Networks

    The authors present the extension of a distributed adaptive fault-detection algorithm applied in networked systems. In previous work, the authors developed an approach to probabilistic detection of communication faults based on measured probe response delays and packet drops. The algorithm is here extended to detect network latency shifts and adapt...

    Provided By Swedish Institute of Computer Science

  • White Papers // Dec 2009

    Making Sensornet MAC Protocols Robust Against Interference

    Radio interference may lead to packet losses, thus negatively affecting the performance of sensornet applications. In this paper, the authors experimentally assess the impact of external interference on state-of-the-art sensornet MAC protocols. Their experiments illustrate that specific features of existing protocols, e.g., hand-shaking schemes preceding the actual data transmission, play...

    Provided By Swedish Institute of Computer Science

  • White Papers // Dec 2009

    Secure Virtualization and Multicore Platforms State-of-the-Art Report

    Virtualization, the use of hypervisors or virtual machine monitors to support multiple virtual machines on a single real machine, is quickly becoming more and more popular today due to its benefits of increased hardware utilization and system management flexibility, and because of increasing hardware and software support for virtualization in...

    Provided By Swedish Institute of Computer Science

  • White Papers // Oct 2009

    Impact Estimation Using Data Flows Over Attack Graphs

    The authors propose a novel approach to estimating the impact of an attack using a data model and an impact model on top of an attack graph. The data model describes how data flows between nodes in the network - how it is copied and processed by softwares and hosts...

    Provided By Swedish Institute of Computer Science

  • White Papers // Oct 2009

    RESTful Wireless Sensor Networks

    Sensor networks have diverse structures and generally employ proprietary protocols to gather useful information about the physical world. This diversity generates problems to interact with these sensors since custom APIs are needed which are tedious, error prone and have steep learning curve. In this paper, the author presents RESThing, a...

    Provided By Swedish Institute of Computer Science

  • White Papers // Jan 2011

    Cross-Level Sensor Network Simulation With COOJA

    Simulators for wireless sensor networks are a valuable tool for system development. However, current simulators can only simulate a single level of a system at once. This makes system development and evolution difficult since developers cannot use the same simulator for both high-level algorithm development and low-level development such as...

    Provided By Swedish Institute of Computer Science

  • White Papers // Jan 2011

    Poster Abstract: Network Coding With Limited Overhearing

    The two key benefits of network coding are increased reliability and throughput. Most network coding approaches for wireless networks rely on overhearing neighboring transmissions. Overhearing in sensor networks, however, is not energy-efficient. In this paper, the authors extend GinMAC, a state-of-the-art MAC protocol, applying network coding with limited overhearing. The...

    Provided By Swedish Institute of Computer Science

  • White Papers // May 2009

    The Impact of Temperature on Outdoor Industrial WSN Applications

    The industrial world is currently considering the adoption of Wireless Sensor Networks (WSNs) for industrial process and control applications. However, when using wireless sensor networks in such application scenarios, network performance, reliability, and robustness must be ensured with high degrees of precision. In this paper the authors study an outdoor...

    Provided By Swedish Institute of Computer Science

  • White Papers // Jan 2010

    Poster Abstract: Storage-Centric Debugging of Performance Problems in Sensor Networks

    After almost ten years of research into sensor networks, deployments continue to fail. Such failures are due to the distributed nature of sensor networks and the complex interactions of protocols. A variety of debugging tools have been developed to determine the exact causes of failures, and to mitigate the poor...

    Provided By Swedish Institute of Computer Science

  • White Papers // Jun 2009

    Low-Power Radio Communication in Industrial Outdoor Deployments: The Impact of Weather Conditions and ATEX-Compliance

    Industry recognizes wireless sensor networks as one of the next major technical and economical shifts in automation and control systems. Industrial applications need performance assurances of wireless communication, which is hard to attain given the variability of the environment where such applications are deployed. In this paper, the authors quantify...

    Provided By Swedish Institute of Computer Science

  • White Papers // Apr 2011

    Leveraging IP for Sensor Network Deployment

    Ease of deployment has always been seen as a major selling point of wireless sensor networks, yet experience has shown deployment to be difficult. The authors argue that parts of these difficulties have come from the lack of a generic networking layer and of well-tested, generic transport protocols in traditional...

    Provided By Swedish Institute of Computer Science

  • White Papers // Dec 2010

    The Announcement Layer: Beacon Coordination for the Sensornet Stack

    Sensornet protocols periodically broadcast beacons for neighborhood information advertisement, but beacon transmissions are costly when power-saving radio duty cycling mechanisms are used. The authors show that piggybacking multiple beacons in a single transmission significantly reduces transmission costs and argue that this shows the need for a new layer in the...

    Provided By Swedish Institute of Computer Science

  • White Papers // Jan 2011

    Using Protothreads for Sensor Node Programming

    Wireless sensor networks consist of tiny devices that usually have severe resource constraints in terms of energy, processing power and memory. In order to work efficiently within the constrained memory, many operating systems for such devices are based on an event-driven model rather than on multi-threading. While event-driven systems allow...

    Provided By Swedish Institute of Computer Science

  • White Papers // Jan 2011

    Experimental Evaluation of Lifetime Bounds for Wireless Sensor Networks

    In this paper the authors present a method for experimental lifetime measurements of sensor networks. Despite the importance of experimental validation, none of the lifetime models proposed so far has been validated experimentally. One of the reasons for the absence of practical validations might be the long lifetime of batteries...

    Provided By Swedish Institute of Computer Science

  • White Papers // Jan 2011

    Contiki - A Lightweight and Flexible Operating System for Tiny Networked Sensors

    Wireless sensor networks are composed of large numbers of tiny networked devices that communicate untethered. For large scale networks it is important to be able to dynamically download code into the network. In this paper the authors present Contiki, a lightweight operating system with support for dynamic loading and replacement...

    Provided By Swedish Institute of Computer Science

  • White Papers // Jan 2009

    Demo Abstract: Seamless Sensor Network IP Connectivity

    Most existing sensor network systems require custom gateways and tools to interface to the Internet. The authors present a seamless IP-based sensor network connectivity mechanism that allows a sensor network to be instantly connected to a PC and additionally to the Internet. They use an IP stack on the sensor...

    Provided By Swedish Institute of Computer Science

  • White Papers // Oct 2008

    Contiki Programming Course: Hands-On Session Notes

    This paper is an introduction to Contiki communication programming - use it as a starting point for further exploration. Feel free to copy the tutorial code in ones' own projects: it is a very good way to learn. Play around with Cooja to get a feeling for how it works....

    Provided By Swedish Institute of Computer Science

  • White Papers // Mar 2010

    Energy Framework: An Extensible Framework for Simulating Battery Consumption in Wireless Networks

    This paper presents the Energy Framework, an extensible OMNeT++ framework for modeling battery consumption in wireless networks, particularly sensor networks. The Energy Framework is highly modular, separating modeling of the internal state of the battery from the modeling of operations that consume energy. This structure enables functionality that is not...

    Provided By Swedish Institute of Computer Science

  • White Papers // Sep 2010

    The Look, the Feel and the Action: Making Sets of ActDresses for Robotic Movement

    The authors present a series of design explorations for controlling autonomous robotic movement based on a metaphor of clothing and accessorising. From working with various sketches, scenarios and prototypes they identify a number of particular features of this form of interaction, as well potential challenges for designers of other systems...

    Provided By Swedish Institute of Computer Science

  • White Papers // Apr 2012

    Do Sensor Networks Need Mobile MAC Protocols?

    There exists a number of MAC protocols targeted for mobile scenarios. These include MMAC, MS-MAC and AM-MAC. These MAC protocols have in common that they seem to be evaluated only in simulation. This might indicate that these MAC are either too complex to use or they are not needed, at...

    Provided By Swedish Institute of Computer Science

  • White Papers // Mar 2012

    Zooming Into Radio Events by Bus Snooping

    In this paper, the authors advocate the use of bus snooping to trace radio events. Highly precise and un-intrusive, the technique leads to potentially more efficient code and enables more insightful protocol analysis than conventional code instrumentation techniques. Communication between Cooperating Objects is typically carried out over a multiple-layer protocol...

    Provided By Swedish Institute of Computer Science

  • White Papers // Feb 2012

    The Bus Goes Wireless: Routing-Free Data Collection With QoS Guarantees in Sensor Networks

    The authors present the Low-power Wireless Bus (LWB), a new communication paradigm for QoS-aware data collection in low-power sensor networks. The LWB maps all communication onto network floods by using Glossy, an efficient flooding architecture for wireless sensor networks. Therefore, unlike current solutions, the LWB requires no information of the...

    Provided By Swedish Institute of Computer Science

  • White Papers // Feb 2012

    Scalable Mining of Common Routes in Mobile Communication Network Traffic Data

    A probabilistic method for inferring common routes from mobile communication network traffic data is presented. Besides providing mobility information, valuable in a multitude of application areas, the method has the dual purpose of enabling efficient coarse-graining as well as anonymisation by mapping individual sequences onto common routes. The approach is...

    Provided By Swedish Institute of Computer Science

  • White Papers // Dec 2011

    Multi-Channel Two-Way Time of Flight Sensor Network Ranging

    Two-way time of Flight (ToF) ranging is one of the most interesting approaches for localization in wireless sensor networking since previous ToF ranging approaches using Commercial Off-The-Shelf (COTS) devices have achieved good accuracy. The COTS-based approaches were, however, evaluated only in line-of-sight conditions. In this paper, the authors extend ToF...

    Provided By Swedish Institute of Computer Science

  • White Papers // Jan 2012

    The ContikiMAC Radio Duty Cycling Protocol

    Low-power wireless devices must keep their radio transceivers off as much as possible to reach a low power consumption, but must wake up often enough to be able to receive communication from their neighbors. This paper describes the ContikiMAC radio duty cycling mechanism, the default radio duty cycling mechanism in...

    Provided By Swedish Institute of Computer Science

  • White Papers // Sep 2011

    Hidden Terminal-Aware Contention Resolution With an Optimal Distribution

    Achieving low-power operation in wireless sensor networks with high data load or bursty traffic is challenging. The hidden terminal problem is aggravated with increased amounts of data in which traditional backoff-based contention resolution mechanisms fail or induce high latency and energy costs. The authors analyze and optimize Strawman, a receiver-initiated...

    Provided By Swedish Institute of Computer Science

  • White Papers // Dec 2009

    Making Sensornet MAC Protocols Robust Against Interference

    Radio interference may lead to packet losses, thus negatively affecting the performance of sensornet applications. In this paper, the authors experimentally assess the impact of external interference on state-of-the-art sensornet MAC protocols. Their experiments illustrate that specific features of existing protocols, e.g., hand-shaking schemes preceding the actual data transmission, play...

    Provided By Swedish Institute of Computer Science

  • White Papers // Mar 2011

    Link Quality Estimation for Future Cooperating Objects

    In order to cooperate, smart objects need to communicate using wireless communication. Wireless communication, however, is inherently unreliable. Towards this end, the sensor networking community has developed a number of metrics for link quality estimation. Most of these metrics, however, are designed for static sensor networks whereas cooperating objects in...

    Provided By Swedish Institute of Computer Science

  • White Papers // Nov 2011

    Precise Packet Loss Pattern Generation by Intentional Interference

    Intermediate-quality links often cause vulnerable connectivity in wireless sensor networks, but packet losses caused by such volatile links are not easy to trace. In order to equip link layer protocol designers with a reliable test and debugging tool, the authors develop a reactive interferer to generate packet loss patterns precisely....

    Provided By Swedish Institute of Computer Science

  • White Papers // Nov 2011

    Middleware For Wireless Sensor Networks: An Outlook

    In modern distributed computing, applications are rarely built directly atop operating system facilities, e.g., sockets. Higher-level middleware abstractions and systems are often employed to simplify the programmer's chore or to achieve interoperability. In contrast, real-world Wireless Sensor Network (WSN) applications are almost always developed by relying directly on the operating...

    Provided By Swedish Institute of Computer Science

  • White Papers // May 2012

    Efficient Mobile Data Collection With Mobile Collect

    The main task of most deployed wireless sensor networks is data collection. While a number of solutions have been designed for static networks, there are currently no widely used data collection algorithms for mobile sensor networks. In this paper, the authors concentrate on scenarios where many nodes, both data sources...

    Provided By Swedish Institute of Computer Science

  • White Papers // Oct 2010

    Efficient Content Distribution in an Information-Centric Hybrid Mobile Network

    Information or content centric networking is believed by many to have great potential to be the appropriate networking paradigm for the future Internet. In information centric networking, focus is shifted from the end-points in the network to the information objects themselves, with less care being placed on from where the...

    Provided By Swedish Institute of Computer Science

  • White Papers // Apr 2011

    The Politecast Communication Primitive for Low-Power Wireless

    In low-power wireless networks, nodes need to duty cycle their radio transceivers to achieve a long system lifetime. Counter-intuitively, in such networks broadcast becomes expensive in terms of energy and bandwidth since all neighbors must be woken up to receive broadcast messages. The authors argue that there is a class...

    Provided By Swedish Institute of Computer Science

  • White Papers // Jun 2010

    A Framework for WirelessHART Simulations

    Due to stringent timing requirements of the WirelessHART protocol, the authors need to extend previously known hybrid simulation approaches with WirelessHART specific functionality. Because of intermediary devices that connect simulation and real environments a communication delay significantly exceeds time boundaries of a WirelessHART slot. The authors' solution is to add...

    Provided By Swedish Institute of Computer Science

  • White Papers // May 2010

    StrawMAN: Making Sudden Traffic Surges Graceful in Low-Power Wireless Networks

    To ensure a long lifetime, sensor networks must operate with a low duty cycle, but the duty cycle must be high enough for the network to handle expected peak traffic loads. Being dimensioned for peak traffic rather than regular traffic leads to shorter lifetimes than necessary. The authors present StrawMAN,...

    Provided By Swedish Institute of Computer Science

  • White Papers // Feb 2010

    Demo Abstract: Smart Antennas Made Practical: The SPIDA Way

    Smart antennas are a specific type of directional antenna able to dynamically control the gain as a function of direction. This contrasts with more traditional directional antennas, where the dynamic ability is missing, and with omni-directional antennas, which are designed to have equal gain in all directions. Because of these...

    Provided By Swedish Institute of Computer Science

  • White Papers // Sep 2010

    Evaluation of an Electronically Switched Directional Antenna for Real-World Low-PowerWireless Networks

    The authors present the real-world evaluation of SPIDA, an electronically switched directional antenna. Compared to most existing work in the field, SPIDA is practical as well as inexpensive. They interface SPIDA with an off-the-shelf sensor node which provides one with a fully working real-world prototype. The authors assess the performance...

    Provided By Swedish Institute of Computer Science

  • White Papers // Sep 2010

    Sepidar: Incentivized Market-Based P2P Live-Streaming on the Gradient Overlay Network

    Live streaming of video content using overlay networks has gained widespread adoption on the Internet. This paper presents Sepidar, a distributed market-based model, which builds and maintains overlay network trees, which are approximately minimal height, for delivering live media as a number of substreams. A streaming tree is constructed for...

    Provided By Swedish Institute of Computer Science

  • White Papers // Jan 2010

    Secure Communication in WirelessHART and Its Integration With Legacy HART

    The WirelessHART is a new standard for Industrial Process Automation and Control, formally released in September 2007. WirelessHART specifications are very well organized in all aspects except security as there are no separate specifications that document security requirements, the security is limited and spread throughout the WirelessHART specifications, and it...

    Provided By Swedish Institute of Computer Science

  • White Papers // Feb 2011

    Long-Term Adaptation and Distributed Detection of Local Network Changes

    The authors present a statistical approach to distributed detection of local latency shifts in networked systems. For this purpose, response delay measurements are performed between neighbouring nodes via probing. The expected probe response delay on each connection is statistically modelled via parameter estimation. Adaptation to drifting delays is accounted for...

    Provided By Swedish Institute of Computer Science

  • White Papers // Feb 2011

    Towards Distributed and Adaptive Detection and Localisation of Network Faults

    The authors present a statistical probing-approach to distributed fault-detection in networked systems, based on autonomous configuration of algorithm parameters. Statistical modelling is used for detection and localisation of network faults. A detected fault is isolated to a node or link by collaborative fault-localisation. From local measurements obtained through probing between...

    Provided By Swedish Institute of Computer Science

  • White Papers // Jul 2009

    Controllable Radio Interference for Experimental and Testing Purposes in Wireless Sensor Networks

    The authors address the problem of generating customized, controlled interference for experimental and testing purposes in Wireless Sensor Networks. The known coexistence problems between electronic devices sharing the same ISM radio band drive the design of new solutions to mitigate interference. The validation of these techniques and the assessment of...

    Provided By Swedish Institute of Computer Science

  • White Papers // Apr 2009

    A Software Radio-Empowered Sensor Network

    Low power wireless sensors are limited by current radio technologies to short communication range and low throughput. The authors envision that future radios with advanced software programmable encoding and modulation will bring sensor networks unprecedented flexibility and performance. The authors have taken a step towards realizing this vision by designing...

    Provided By Swedish Institute of Computer Science

  • White Papers // May 2009

    Quality Aspects of Internet Telephony

    Internet telephony has had a tremendous impact on how people communicate. Many now maintain contact using some form of Internet telephony. Therefore the motivation for this work has been to address the quality aspects of real-world Internet telephony for both fixed and wireless telecommunication. The focus has been on the...

    Provided By Swedish Institute of Computer Science