Now showing 1 - 10 of 26
  • Publication
    The clarity modular ambient health and wellness measurement platform
    Emerging healthcare applications can benefit enormously from recent advances in pervasive technology and computing. This paper introduces the CLARITY Modular Ambient Health and Wellness Measurement Platform, which is a heterogeneous and robust pervasive healthcare solution currently under development at the CLARITY Center for Sensor Web Technologies. This intelligent and context-aware platform comprises the Tyndall Wireless Sensor Network prototyping system, augmented with an agent-based middleware and frontend computing architecture. The key contribution of this work is to highlight how interoperability, expandability, reusability and robustness can be manifested in the modular design of the constituent nodes and the inherently distributed nature of the controlling software architecture.
      841Scopus© Citations 5
  • 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.
      891Scopus© Citations 2
  • 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.
      608Scopus© Citations 8
  • Publication
    MERLIN: A synergetic integration of MAC and Routing Protocol for Distributed Sensor Networks
    Notoriously, energy-efficient MAC protocols cause high latency of packets. Such delays may well increase when a routing protocol is applied. Therefore, quantifying the endto- end delay and energy consumption when low duty cycle MAC and routing protocols are jointly used, is of particular interest. In this paper, we present a comprehensive evaluation of the MERLIN (MAC and Efficient Routing integrated with support for localization) protocol. MERLIN integrates MAC and routing features into a single architecture. In contrast to many sensor network protocols, it employs a multicast upstream and multicast downstream approach to relaying packets to and from the gateway. Simultaneous reception and transmission errors are notified by using asynchronous burst ACK and negative burst ACK. A division of the network into timezones, together with an appropriate scheduling policy, enables the routing of packets to the closest gateway. An evaluation of MERLIN has been conducted through simulation, against both the SMAC and the ESR routing protocols,which is an improved version of the DSR algorithm. The results illustrate how both SMAC and ESR, jointly used in low duty cycle scenarios, can cause an impractical and very high end-to-end delays. MERLIN, as an integrated approach, notably reduces the latency, resulting in nodes that can operate in a very low duty cycle. Consequently, an extension of the operative lifetime of the sensor network is achieved.
      459Scopus© Citations 12
  • Publication
    Embedding intelligent decision making within complex dynamic environments
    Decision-making is a complex and demanding process often constrained in a number of possibly conflicting dimensions including quality, responsiveness and cost. This paper considers in situ decision making whereby decisions are effected based upon inferences made from both locally sensed data and data aggregated from a sensor network. Such sensing devices that comprise a sensor network are often computationally challenged and present an additional constraint upon the reasoning process. This paper describes a hybrid reasoning approach to deliver in situ decision making which combines stream based computing with multi-agent system techniques. This approach is illustrated and exercised through an environmental demonstrator project entitled SmartBay which seeks to deliver in situ real time environmental monitoring.
      1339Scopus© Citations 12
  • 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.
      802Scopus© Citations 12
  • 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.
      2826Scopus© Citations 45
  • Publication
    Multi-hop RFID wake-up radio : design, evaluation and energy tradeoffs
    Energy efficiency is a central challenge in battery operated sensor networks. Current energy-efficient mechanisms employ either duty cycling, which reduces idle listening but does not eliminate it, or low power wake-up radio, which adds complexity and cost to the sensor platform. In this paper, we propose a novel mechanism called RFIDImpulse that uses RFID technology as an out-of-band wake-up channel for sensor networks. RFIDImpulse is an on-demand mechanism that enables nodes to sleep until they have to send or receive packets. It relies on IEEE 802.15.4 radio to emulate an RFID reader at a sender node, and on an off-the-shelf RFID tag attached to the external interrupt pin of each sensor node. The sender can simply activate the receiver’s tag before sending it data packets. This setup enables both radio and microcontroller to go into deep sleep mode until they need to be active. We develop an analytical model to evaluate the energy tradeoffs of RFIDImpulse, and then evaluate the mechanism against BMAC and IEEE 802.15.4 in high and low traffic scenarios. The results confirm that RFIDImpulse reduces the energy consumption relative to both protocols for low and medium traffic scenarios, and they reveal the thresholds for adaptive activation of RFIDImpulse based on traffic load.
      1110Scopus© Citations 31
  • Publication
    Coordinated sleeping for beaconless 802.15.4-based multihop networks
    The last few years have seen a wide adoption of the IEEE 802.15.4 MAC/PHY standard for low-power communication between wireless sensor nodes. Within this work we study some fundamental drawbacks of the 802.15.4 specifications for multihop network deployments, which adversely affect the delivery rate and efficient node energy consumption. These issues are rectified by investigating a timezone-based scheduling, V-Route, that builds on 802.15.4 beaconless mode to enable both a synchronized sleep scheduling and a bidirectional communication between nodes in the sensor network and the PAN coordinator. The contributions of V-Route are threefold: (1) mitigate collisions, (2) enable packet routing and (3) provide energy saving in a multihop context, while maintaining the full compliancy with the 802.15.4 standard. We present a performance evaluation on energy consumption and latency with real experiments on Philips AquisGrain sensor nodes. Enhancing 802.15.4-based multi-hop networks with V-Route yields energy reduction ranging from 27.3% to 85.3%, according to the required end-to-end latency.
      2077Scopus© Citations 2
  • Publication
    A Low-Latency Routing Protocol for Wireless Sensor Networks
    Recent advances in wireless sensors network (WSN) technology have made possible the manufacturing of tiny low-cost, low-power sensors with wireless multi-hop communication and sensing capabilities. Energy conservation for WSNs is a primary objective that needs to be addressed at all layers of the networking protocol stack. In many applications latency is another crucial factor to be addressed. However this must be done in the context of the energy constraints imposed by the network. In this paper we present an experimental evaluation of two node scheduling regimes within MERLIN (MAC energy efficient, routing and localization integrated), an energy-efficient low-latency integrated protocol for WSNs. In particular we contrast the X and V scheduling family schemes with respect to the following properties: network setup time, network lifetime and message latency. We conduct our experiments within the OmNet++ simulator.
    Scopus© Citations 15  322