Search results for "Network"

On the de-energization of over-head low-voltage lines under high-impedance fault conditions

2018

Downed distribution conductors in overhead distribution systems, may not be a concern for equipment, but greatly challenge the safety of persons, as well as the integrity of properties. Upstream overcurrent protective devices may not be able to detect the magnitudes of fault currents resulting from these high-impedance faults. Even though protective devices capable to detect such faults have been available on the market, not all the utilities have equipped their stations with these products, likely due to the costs. In this paper, the authors formalize the problem, and propose a possible cost-effective solution for the low-voltage over-head lines with neutral wire. Such solution includes a …

LifeRescue: A web based application for emergency responders during fire emergency response

2016

In order to respond to any kind of building fire emergencies, first-responders have to use lot of time to get access to the emergency data such as location of the victims who are still inside the building, location of the hazardous material, location of the resources and location of the exits in order to perform search and rescue. However, search is possibly one of the most dangerous activities on the fire ground. Sometimes the visibility is zero and the environment is really hot. Because of the limited operating time in the building, the key to successful search is how quickly emergency responders can get access to the emergency related information in order to save victims and the property…

Towards Risk-aware Access Control Framework for Healthcare Information Sharing

2018

Improving the multiple errors detection coverage in distributed embedded systems

2004

Currently, a lot of critical applications in automobile and aircraft avionics are built on fault-tolerant real-time distributed embedded systems. Fault injection techniques have been used extensively in the experimental validation of these systems and it is a challenge to adapt them to the demands of new technologies. This paper deals with the effect of physical faults at pin level on the Communication Network Interface in a prototype based on time-triggered architecture. Due to the essential necessity of observing system behavior during injection experiments, a suitable monitor for distributed embedded systems is proposed. The monitor is used to detect failures in the value domain that cou…

Analysis on channel bonding/aggregation for multi-channel cognitive radio networks

2010

Channel bonding/aggregation techniques, which assemble several channels together as one channel, could be used in cognitive radio networks for the purpose of achieving better bandwidth utilization. In existing work on this topic, channel bonding/aggregation is focused on the cases when primary channels are time slotted or stationary as compared with secondary users' activities. In this paper, we analyze the performance of channel bonding/aggregation strategies when primary channels are not time slotted and the time scale of primary activities is at the same level as the secondary users', given that spectrum handover is not allowed. Continuous time Markov chain models are built in order to a…

5G V2V Communication With Antenna Selection Based on Context Awareness: Signaling and Performance Study

2022

Enhanced vehicle-to-everything (eV2X) communication is one of the key challenges to be addressed by the fifth generation (5G) of cellular mobile communications. In particular, eV2X includes some 5G vehicular applications targeting fully autonomous driving which require ultra-high reliability. Although vehicular communications are by default assumed between single antennas located on the roof of the transmitter and receiver vehicles, prior art has shown that there are other antenna positions more suitable for V2X communication, depending on the specific communication context. Antenna selection can be used in this case to select one specific antenna or a subset of them better suited for a cer…

Virtualization of Remote Devices and Services in Residential Networks

2009

Lately solutions for remote access for residential services have been proposed. However, these solutions require modifications to the service controllers. In addition, remote access adds complexity to the client application. We propose here a solution for decoupling remote access from the client itself with an entity that creates virtual instances of remote services in a local network. Thereby, clients will be able to discover the virtual instance and use it. Moreover, client applications do not need to distinguish between local and remote services hence reducing complexity.

Security in mobile agent systems

2007

Priority Enabled Grant-Free Access With Dynamic Slot Allocation for Heterogeneous mMTC Traffic in 5G NR Networks

2021

Although grant-based mechanisms have been a predominant approach for wireless access for years, the additional latency required for initial handshake message exchange and the extra control overhead for packet transmissions have stimulated the emergence of grant-free (GF) transmission. GF access provides a promising mechanism for carrying low and moderate traffic with small data and fits especially well for massive machine type communications (mMTC) applications. Despite a surge of interest in GF access, how to handle heterogeneous mMTC traffic based on GF mechanisms has not been investigated in depth. In this paper, we propose a priority enabled GF access scheme which performs dynamic slot …

DTMC modeling for performance evaluation of DW-MAC in wireless sensor networks

2016

Synchronized duty cycling (DC) aligns sensor nodes to wake up at the same time in order to reduce idle listening for medium access control (MAC) in wireless sensor networks (WSNs). Demand wakeup MAC (DW-MAC) is a popular synchronous DC MAC protocol which allows nodes to compete and transmit multiple packets in one operational cycle. This multiple packet transmission (MPT) feature makes DW-MAC more energy efficient when comparing with other existing single time competition based protocols such as sensor MAC (S-MAC). In the literature, no analytical model exists to evaluate the performance of DW-MAC. In this paper, we develop two associated discrete time Markov chain (DTMC) models and incorpo…