Now showing 1 - 10 of 13
  • Publication
    Portability in MAC protocol and transceiver software implementations for LR-WPAN platforms
    In a variety of emerging networked computing system domains over the years, there have been bursts of activity on new medium access control (MAC) protocols, as new communication transceiver technologies with greater data-movement performance or lower power dissipation have been introduced. To enable implementations flexible to evolving standards and improving application-domain insight, such MAC protocols are typically initially implemented in software, and interface between applications or system software, typically executing on an embedded processor or microcontroller, and the evolving radio transceiver hardware. Many challenges exist in implementing MAC protocols across evolving or competing transceiver hardware implementations and processor architectures. Some of these challenges are peculiar to the requirements of MAC protocols, and others are a result of the plethora of system and processor architectures in the embedded systems domain. This article studies the challenges facing software implementations of MAC protocols running on embedded microcontrollers, and interfacing with radio transceiver hardware. Experience with an implementation of the IEEE 802.15.4 MAC across three hardware platforms with different processor, system, and systems software architectures is presented, focusing on implementation approach and interfaces. Pitfalls are pointed out, and guidelines are provided for ensuring that new MAC implementations are easily portable across processor architectures and transceiver hardware.
  • Publication
    Autonomous management and control of sensor network-based applications
    A central challenge facing sensor network research and development is the difficulty in providing effective autonomous management capability. This is due to a large number of parameters to control, unexpected changes of the network topology and dynamic application requirements. Network management is also a challenging task for the remote user due to the large-scale of the network and scarce visibility of live network happenings. Preferably the network should have autonomous decision-making capabilities as network conditions and application requirements changes. To cope with such uncertainties, firstly we consider Octopus, a powerful software tool that provides live information about the network topology and sensor data. At present, the tool can provide monitoring and require a user to control the network state manually. This paper describes how Octopus is reengineered to accommodate a multi-agent system to provide autonomic managing capabilities. In particular, we detail two distinct architectures, the static and mobile agent architectures, which can be effectively applied to deliver autonomous system management. This paper sets the basis for a full autonomous network management via a multi agent system to work with Octopus.
      1089Scopus© Citations 1
  • Publication
    Demo abstract : appliance load monitoring by power load disaggregation
    Appliance load monitoring systems are designed to disaggregate the power load of a building in order to estimate the nature of individual loads, providing a real-time fine-grained recognition of active appliances. Monitoring non-intrusively appliances’ contributions to a given load enables a wide range of applications, ranging from electricity bill decomposition to accurate electricity user profiling. This work demonstrates a real implementation of such appliance load monitoring system. An intuitive graphical user interface is proposed to drive the system setup for profiling appliances’ signatures and for visualising the monitoring output.
      841Scopus© Citations 2
  • Publication
    ANNOT : Automated electricity data annotation using wireless sensor networks
    Recent advances in low-power wireless networking have enabled remote and nonintrusive access to households’ electric meter readings, allowing direct real-time feedback on electricity consumption to home owners and energy providers. Fine-grained electricity billing based on appliance power load monitoring has been investigated for more than two decades, but has not yet witnessed wide commercial acceptance. In this paper, we argue that the required human supervision for profiling and calibrating appliance load monitoring systems is a key reason preventing large-scale commercial roll-outs.We propose ANNOT, a system to automate electricity data annotation leveraging cheap wireless sensor nodes. Characteristic sensory stimuli captured by sensor nodes placed next to appliances are translated into appliance operating state and correlated to the electricity data, autonomously generating the annotation of electricity data with appliance activity. The system is able to facilitate the acquisition of appliance signatures, training data and validate the monitoring output. We validate the concept by integrating the automated annotation system to the RECAP appliance load monitoring system.
      2670Scopus© Citations 44
  • Publication
    NetBem : business equipment energy monitoring through network auditing
    Modern office buildings are fully equipped and furnished spaces with arrangements including networked business equipment, such as PC-class machines, copiers, wireless routers and fax machines, and other electrical equipment such as home appliances e.g. coffee machines, and appliances for environmental comfort e.g. electric heaters. The unique characteristics of networked business equipment are well-defined usage pattern, low-power current draw, and connectivity to the local area network (LAN). Business equipment is generally used over working hours adding up to important costs, motivating the need for a system capable of tracking equipment usage and associated energy expenditure, as well as identifying cost saving opportunities. Techniques for monitoring power loads are generally based on power step edge detection, and cannot be applied to business equipment due to the low power consumption of individual devices. This paper presents NetBem, a novel energy monitoring technique ad hoc to office buildings, capturing the contribution of networked business equipment to a power load via side-band detection of the equipment’s operating state through the LAN. The technique is presented, and results from experiments within the School of Computer Science and Informatics at University College Dublin in Ireland are given.
      568Scopus© Citations 8
  • Publication
    Real-time recognition and profiling of appliances through a single electricity sensor
    Sensing, monitoring and actuating systems are expected to play a key role in reducing buildings overall energy consumption. Leveraging sensor systems to support energy efficiency in buildings poses novel research challenges in monitoring space usage, controlling devices, interfacing with smart energy meters and communicating with the energy grid. In the attempt of reducing electricity consumption in buildings, identifying individual sources of energy consumption is key to generate energy awareness and improve efficiency of available energy resources usage. Previous work studied several non-intrusive load monitoring techniques to classify appliances; however, the literature lacks of an comprehensive system that can be easily installed in existing buildings to empower users profiling, benchmarking and recognizing loads in real-time. This has been a major reason holding back the practice adoption of load monitoring techniques. In this paper we present RECAP: RECognition of electrical Appliances and Profiling in real-time. RECAP uses a single wireless energy monitoring sensor easily clipped to the main electrical unit. The energy monitoring unit transmits energy data wirelessly to a local machine for data processing and storage. The RECAP system consists of three parts: (1) Guiding the user for profiling electrical appliances within premises and generating a database of unique appliance signatures; (2) Using those signatures to train an artificial neural network that is then employed to recognize appliance activities (3) Providing a Load descriptor to allow peer appliance benchmarking. RECAP addresses the need of an integrated and intuitive tool to empower building owners with energy awareness. Enabling real-time appliance recognition is a stepping-stone towards reducing energy consumption and allowing a number of major applications including load-shifting techniques, energy expenditure breakdown per appliance, detection of power hungry and faulty appliances, and recognition of occupant activity. This paper describes the system design and performance evaluation in domestic environment.
      2818Scopus© Citations 215
  • Publication
    Debugging low-power and lossy wireless networks : a survey
    Recent economic and technical advances in wireless communication have allowed the deployment of low-power and lossy wireless networks—LowPANs, potentially comprised of a large number of nodes to serve new types of applications. However, the resource-constrained nature of microsensor platforms together with the unreliability and low-bandwidth of low-power and lossy wireless links have increased the risk and occurrence of network failures. Unlike with traditional wireless networks and controlled pre-deployment simulations and laboratory setups, likely events such as node crashes, inefficient networking and environmental interferences can potentially freeze a network post deployment. A survey of existing tools and related work in debugging LowPANs is presented, to provide a comprehensive state of the art of debugging tools and techniques. We divide debugging tools in two categories, pre-deployment tools and post-deployment tools, and evaluate their performance and limitations. From this study, we discuss the challenges in debugging LowPANs, providing the main issues and requirements that LowPANs’ specific constraints impose on debugging tools, to help developers choose the appropriate tool for specific needs.
      1248Scopus© Citations 18
  • Publication
    A framework for time-controlled and portable WSN applications
    Body sensor network applications require a large amount of data to be communicated over radio frequency. The radio transceiver is typically the largest source of power dissipation; improvements on energy consumption can thus be achieved by enabling on-node processing to reduce the number of packets to be transmitted. On-node processing is facilitated by a timely control over process execution to sequence operations on data; yet, the latter must be enabled while keeping highlevel software abstracted from both underlying software and hardware intricacies to accommodate portability to the wide range of hardware and software platforms. We investigated the challenges of implementing software services for on-node processing and devised constructs and system abstractions that integrate applications, drivers, time synchronization and MAC functionality into a system software which presents limited dependency between components and enables timely control of processes. We support our claims with a performance evaluation of the software tools implemented within the FreeRTOS micro-kernel.
      1703Scopus© Citations 1
  • Publication
    COPOLAN : non-invasive occupancy profiling for preliminary assessment of HVAC fixed timing strategies
    Nowadays, control of heating, cooling and ventilation equipment operation is mainly achieved via timers with fixed setback schedules, configured using experience and standard models of space occupancy. Applying generic timing strategies is however rarely optimal. Sensor-based systems offer a solution for dynamic control of equipment operation using real-time space occupancy input, but both deployment time and cost constraints hinder their integration if savings and return on investment are uncertain. This work introduces COPOLAN, a tool that correlates power consumption pat- terns and computers’ VLAN activity. Utilising computers’ VLAN activity auditing is key to obtain the power state of employees’ computer equipment over time, a prime indicator of employees’ presence within a building. At low cost and non-invasively, COPOLAN uncovers misalignment and pro- duces ground for (1) determining opportunities of improv- ing HVAC timing strategies and (2) helping decision making prior to integrating new equipment such as sensor-based systems. COPOLAN has been experimented on within a University department, where misalignment between power consumption and space occupancy patterns have highlighted 10 % energy saving opportunities.
      720Scopus© Citations 12
  • Publication
    Intelligent middleware for adaptive sensing of tennis coaching sessions
    In professional tennis training matches, the coach needs to be able to view play from the most appropriate angle in order to monitor players activities. In this paper, we present a system which can adapt the operation of a series of cameras in order to maintain optimal system performance based on a set of wireless sensors. This setup is used as a testbed for an agent based intelligent middleware that can correlate data from many different wired and wireless sensors and provide effective in-situ decision making. The proposed solution is flexible enough to allow the addition of new sensors and actuators. Within this setup we also provide details of a case study for the embedded control of cameras through the use of Ubisense data.
      789Scopus© Citations 1