Search results for "Networking & Telecommunications"
showing 10 items of 962 documents
Efficient information gathering from large wireless sensor networks
2018
Abstract Considering large WSNs and comparing data aggregation approaches in terms of scalability, robustness, completeness, and time/energy effectiveness, recent research has asserted the superiority of serial structure-free approaches over serial structure-based ones, and over both parallel structure-free and parallel structure-based techniques. But, in spite of the fact that serial structure-free approaches excel in large and medium-scale networks, their underlying path-construction algorithms are not optimal and can be improved by reducing the involved communications and further shortening the visiting path. To respond to this need, this paper presents Geometric Serial Search (GSS); a n…
Performance of frame transmissions and event-triggered sleeping in duty-cycled WSNs with error-prone wireless links
2018
Abstract Two types of packet transmission schemes are prevalent in duty-cycled wireless sensor networks, i.e., single packet transmission and aggregated packet transmission which integrates multiple packets in one frame. While most existing models are developed based on an error-free channel assumption, this paper evaluates the performance of both transmission schemes under error-prone channel conditions. We develop a four-dimensional discrete-time Markov chain model to investigate the impact of channel impairments on the performance of frame transmissions. Together with tracking the number of packets in the queue, number of retransmissions and number of active nodes, the fourth dimension o…
Enabling early sleeping and early data transmission in wake-up radio-enabled IoT networks
2019
Abstract Wireless sensor networks (WSNs) are one of the key enabling technologies for the Internet of things (IoT). In such networks, wake-up radio (WuR) is gaining its popularity thanks to its on-demand transmission feature and overwhelming energy consumption superiority. Despite this advantage, overhearing still occurs when a wake-up receiver decodes the address of a wake-up call (WuC) which is not intended to it, causing a certain amount of extra energy waste in the network. Moreover, long latency may occur due to WuC address decoding since WuCs are transmitted at a very low data rate. In this paper, we propose two schemes, i.e., early sleeping (ES) and early data transmission (EDT), to …
A Predictive Approach for the Efficient Distribution of Agent-Based Systems on a Hybrid-Cloud
2018
International audience; Hybrid clouds are increasingly used to outsource non-critical applications to public clouds. However, the main challenge within such environments, is to ensure a cost-efficient distribution of the systems between the resources that are on/off premises. For Multi Agent Systems (MAS), this challenge is deepened due to irregular workload progress and intensive communication between the agents, which may result in high computing and data transfer costs. Thus, in this paper we propose a generic framework for adaptive cost-efficient deployment of MAS with a special focus on hybrid clouds. The framework is based mainly on the use of a performance evaluation process that con…
Ultra-Low Power Wake-up Radio for 5G IoT
2019
5G Internet of Things (5G IoT), which is currently under development by 3GPP, paves the way for connecting diverse categories of devices to the IoT via cellular networks. For battery-powered low-cost IoT devices, wake-up radio (WuR) appears as an eminent technique for prolonging the lifetime of such devices, thanks to its outstanding energy consumption performance. However, only some small-size battery-powered IoT devices are able to transmit to a cellular IoT base station (BS) directly. In this article, we present W2B-IoT, a prototype implementation of a WuR-based two-tier system, which bridges cellular IoT BS and WuR via a Bluetooth low energy (BLE)-enabled Android smartphone. Such a WuR-…
Non-cooperative power allocation game with imperfect sensing information for cognitive radio
2012
In this paper, we consider a sensing-based spectrum sharing scenario and present an efficient decentralized algorithm to maximize the total throughput of the cognitive radio users by optimizing jointly both the detection operation and the power allocation, taking into account the influence of the sensing accuracy. This optimization problem can be formulated as a distributed non-cooperative power allocation game, which can be solved by using an alternating direction optimization method. The transmit power budget of the cognitive radio users and the constraint related to the rate-loss of the primary user due to the interference are considered in the scheme. Finally, we use variational inequal…
Angle and Height Estimation Technique for Aerial Vehicles using mmWave FMCW Radar
2021
In this article, we present a novel angle and height estimation technique for aerial vehicles using mmWave frequency modulated continuous wave (FMCW) Radar. In the proposed method, Radar’s antennas are oriented vertically to measure the elevation angle of arrival of the aerial vehicle from ground station. Height of the aerial vehicle and horizontal distance of the aerial vehicle from Radar station on ground are estimated using the measured radial range and the elevation angle of arrival.
Spectrogram Analysis of Multipath Fading Channels under Variations of the Mobile Speed
2016
When modelling, analysing, and simulating mobile radio channels, it is generally assumed that the speed of the mobile station (MS) is constant. In practice, however, the mobile speed varies with time. Mobile speed variations result in nonwide- sense stationary multipath fading channels, which can be modelled by a sum-of-chirps (SOCh) processes. In this paper, we analyse the local Doppler power spectral density (PSD) of SOCh processes by using the concept of the spectrogram. The spectrogram provides an estimate of the local Doppler PSD and gives insight into how the Doppler PSD changes over time if the MS increases or decreases its speed. A closed-form solution is presented for the spectrogr…
How does serendipity affect diversity in recommender systems? A serendipity-oriented greedy algorithm
2018
Most recommender systems suggest items that are popular among all users and similar to items a user usually consumes. As a result, the user receives recommendations that she/he is already familiar with or would find anyway, leading to low satisfaction. To overcome this problem, a recommender system should suggest novel, relevant and unexpected i.e., serendipitous items. In this paper, we propose a serendipity-oriented, reranking algorithm called a serendipity-oriented greedy (SOG) algorithm, which improves serendipity of recommendations through feature diversification and helps overcome the overspecialization problem. To evaluate our algorithm, we employed the only publicly available datase…
Topology Inference and Signal Representation Using Dictionary Learning
2019
This paper presents a Joint Graph Learning and Signal Representation algorithm, called JGLSR, for simultaneous topology learning and graph signal representation via a learned over-complete dictionary. The proposed algorithm alternates between three main steps: sparse coding, dictionary learning, and graph topology inference. We introduce the “transformed graph” which can be considered as a projected graph in the transform domain spanned by the dictionary atoms. Simulation results via synthetic and real data show that the proposed approach has a higher performance when compared to the well-known algorithms for joint undirected graph topology inference and signal representation, when there is…