Search results for "Distributed computing"

MCD: Overcoming the Data Download Bottleneck in Data Centers

2013

The data download problem in data centers describes the increasingly common task of coordinated loading of identical data to a large number of nodes. Data download is seen as a significant problem in exascale HPC applications. Uncoor-dinated reading from a central file server creates contention at the file server and its network interconnect. We propose and evaluation a reliable multicast based approach to solve the data download problem. The MCD system builds a logical multi-rooted tree based on the physical network topology and uses the logical view for a two-phase approach. In the first phase, the data is multicasted to all nodes. In the second phase, the logical tree is used for an effi…

MPWCA-L: A New Clustering Algorithm to Improve Stability and QoS in MANETs

2013

Semantic and Logic Modeling of Disaster Simulation for Multi-agent Systems

2019

Distributed Symbolic Network Quality Assessment for Resource-constrained Devices

2021

After a Wireless Sensor Network (WSN) is deployed it is subject to significant variations of the quality of its radio links during its lifetime. Knowledge of the condition of the wireless links can be useful to optimize power consumption and increase the reliability of the network. However, resource-constrained nodes may not be able to spare the storage space for network monitoring code. Also, reprogramming deployed nodes can be costly or unfeasible. In this work, we show how an approach based on the exchange of symbolic executable code among nodes enables the assessment of the network status in terms of Packet Reception Rate (PRR) with no extra storage requirements on deployed networks. We…

Fuzzy Logic based model for self-optimizing energy consumption in IoT environment

2021

Energy optimization is essential in IoT environments due to energy constraints for some IoT components. In fact, energy consumption has a direct impact on IoT system lifetime, which represents an important Quality of Service (QoS) parameter for IoT environments. In order to extend the IoT system lifetime, energy consumption optimization should be considered in several IoT components. In this paper, we specify an energy self-optimizing mechanism allowing to minimize data transmission energy consumption of IoT objects. This mechanism enables selecting specific objects to send the desired data while minimizing the energy consumed for the corresponding communication. Our proposal is made of a M…

Distributed Computing on Distributed Memory

2018

Distributed computation is formalized in several description languages for computation, as e.g. Unified Modeling Language (UML), Specification and Description Language (SDL), and Concurrent Abstract State Machines (CASM). All these languages focus on the distribution of computation, which is somewhat the same as concurrent computation. In addition, there is also the aspect of distribution of state, which is often neglected. Distribution of state is most commonly represented by communication between active agents. This paper argues that it is desirable to abstract from the communication and to consider abstract distributed state. This includes semantic handling of conflict resolution, e.g. i…

Energy-Efficient Context-Aware Resource Allocation for Edge-Computing-Empowered Industrial IoT

2020

Edge computing provides a promising paradigm to support the implementation of industrial Internet of Things (IIoT) by offloading computational-intensive tasks from resource-limited machine-type devices (MTDs) to powerful edge servers. However, the performance gain of edge computing may be severely compromised due to limited spectrum resources, capacity-constrained batteries, and context unawareness. In this chapter, we consider the optimization of channel selection which is critical for efficient and reliable task delivery. We aim at maximizing the long-term throughput subject to long-term constraints of energy budget and service reliability. We propose a learning-based channel selection fr…

Context-Aware RF-Energy Harvesting for IoT Networks

2021

Energy Harvesting plays a crucial role in improving the operational lifetime of IoT devices. The deployment of dedicated RF-transmitters helps in sufficient energy propagation to the sensor nodes of IoT networks. Also, energy harvesting using the deployment of such RF-transmitters is a challenging issue. In this work, two methods are proposed for the optimal placement of RF-transmitters for efficient energy harvesting in wireless sensor networks. The proposed context-aware RF-energy harvesting considers different network performance parameters such as energy-hole information, and data routing information. RF-transmitter deployment is achieved using network connectivity information in the fi…

A Comparison Study of Metaheuristic Techniques for Providing QoS to Avatars in DVE Systems

2004

Network-server architecture has become a de-facto standard for Distributed Virtual Environment (DVE) systems. In these systems, a large set of remote users share a 3D virtual scene. In order to design scalable DVE systems, different approaches have been proposed to maintain the DVE system working under its saturation point, maximizing system throughput. Also, in order to provide quality of service to avatars in a DVE systems, avatars should be assigned to servers taking into account, among other factors, system throughput and system latency. This highly complex problem is called quality of service (QoS) problem in DVE systems. This paper proposes two different approaches for solving the QoS…

The role of the Access Point in Wi-Fi networks with selfish nodes

2009

In Wi-Fi networks, mobile nodes compete for accessing the shared channel by means of a random access protocol called Distributed Coordination Function (DCF), which is long term fair. But recent drivers allow users to configure protocol parameters differently from their standard values in order to break the protocol fairness and obtain a larger share of the available bandwidth at the expense of other users. This motivates a game theoretical analysis of DCF. Previous studies have already modeled access to a shared wireless channel in terms of non-cooperative games among the nodes, but they have mainly considered ad hoc mode operation. In this paper we consider the role of the Access Point (AP…